At one time or another ASC, which is headquartered in Southgate, Michigan, operated plants or design/engineering studios in: Kitchener, Ontario, Canada - Rancho Dominquez (Long Beach), California - Huntington Beach, California – Columbus, Ohio – Lordstown, Ohio - Bowling Green, Kentucky – Detroit, Michigan - Lansing, Michigan - Southgate, Michigan - Owosso, Michigan – Gibraltar, Michigan - Warren, Michigan - Oak Park, Michigan – East Tawas, Michigan - Linden, New Jersey - Bloomington, Illinois - Spartanburg, South Carolina - Atlanta, Georgia -Munich, Germany - Heilbronn, Germany – Weinsberg, Germany - Youngshon, South Korea – Martorell, Spain.
ASC was founded in late 1963 by Heinz Christian Prechter, a German foreign exchange student who was attending San Francisco State College. Born on January 19, 1942, Prechter was brought up on his family’s Kleinhöbing, Bavaria farm. He was fascinated by automobiles from an early age and entered the automotive apprenticeship program at the local Berufschule (vocational school) when he was 13. After school Prechter worked at his uncle’s auto repair shop, and following the successful completion of his studies, he was accepted at the Nuremburg Berufs-Oberschule (upper vocational school) where he interned at Deutz (diesel engines & tractors), Faunwerke (trucks and military vehicles) and Siemens (electronics).
Following his graduation, Prechter was accepted into the mechanical engineering program at the prestigious Georg Simon Ohm Polytechnic in Nuremberg. Prechter moonlighted as a cab driver, eventually saving up enough money to finance a trip to the United States in 1961 where he attended San Francisco State College as an exchange student.
While attending Ohm Polytechnic, Prechter had become friends with Hans-Dieter Golde, the son of Hans Traugotte Golde, the founder of Hans Traugotte Golde & Co., Frankfurt (aka Golde Schiebedächer) an early manufacturer of sliding canvas and metal sunroofs. Golde roofs were optional equipment on 1950s-1960s BMWs, Porsche 356s and Volkswagen Type 1 (Beetle), Type 14 (Karmann Ghia) and Type 2 (Kombi & Samba).
In 1957 Golde & Co. established a sales office in Detroit that was headed by Guenter H. Sleboede. Early customers included Studebaker who offered a ‘Sky Top’ option on many of their 1960-1963 vehicles. Another customer was Ford, who had Budd install 2,536 roofs on their ‘Golde Edition’ 1960 Thunderbird.
Golde Body Parts Division was originally located at 6406 Charlevoix Ave., but when manufacturer’s orders for the roofs dried up in 1962, the German firm withdrew its financial support. Golde allowed Sleboede to represent the firm as its regional Detroit distributor, so he relocated to 32940 Van Dyke in Warren, Michigan where he established the A-One Service Center. Sleboede continued to supply Golde kits to regional auto dealers and also maintained a small shop where the tops could be installed in customer’s cars.
While completing his studies in business administration and English at Cal-State, Heinz C. Prechter worked part-time for a small San Francisco body shop owned by a Mr. Forster. He suggested that they get into the sunroof business and using his Golde family connection, Prechter was awarded Golde’s west coast distributorship. In late 1963, Golde and Forster formed the American Sunroof Corp. and started advertising in the local papers.
American Sunroof’s first customers were regional San Francisco and San Mateo new car dealers and although Prechter had originally planned on staying in the US for a single year, he decided to stay and applied for a working visa which was granted in December of 1964.
Business at American Sunroof’s 1419 Pacific Ave., San Francisco workshop steadily improved and in January of 1965 Prechter opened up a branch in Los Angeles. Car customizer George Barris had a garage for rent behind his 10811 Riverside Dr., North Hollywood, California shop and it was here that Prechter established American Sunroof’s first metro Los Angeles branch.
Early on, Prechter put sunroofs in cars owned by Hollywood celebrities who included Frank Sinatra, James Garner and Steve McQueen. He soon outgrew the cramped two-car garage behind Barris Kustom City and relocated to a former gas station at 7322 Quinby St. in Paramount, California.
In 1966 Prechter brought his 19-year-old brother Christian from Germany to manage his LA operations. A number of mid-60s Barris-built show cars featured sunroofs installed by American. Barris’ 1965 Buick Wildcat-based Mystique showcar and personal tangerine 1966/67 Riviera both had them.
George Barris had recently established a relationship with the Ford for whom he built the Super Marauder showcar. Custom cars were becoming very popular at the time, so Ford selected two West Coast customizers, Barris and Gene Winfield, to produce a pair of showcars for the upcoming fall auto shows. Barris was given a prototype 1964 Mercury Marauder Convertible by Ford’s L. David Ash who oversaw the project.
When Ford approached Barris the following year to see if he could install a sunroof in a Lincoln, Prechter was the man Barris recommended the job. When he first started working with Ford, he placed sunroofs in a number of VIP vehicles, one of which was delivered to President Lyndon B. Johnson. Prechter found himself doing more and more special projects for Ford and in early 1967 got a contract to install sunroofs on 200 1967 Mercury Cougars.
Prechter completed the first batch of cars in June of 1967 in a former carwash located in the 100 block of Southfield Road in Ecorse, Michigan, a few blocks west of the Detroit River. The carwash conveniently backed up to a small railyard where the Cougars were offloaded from railcars and parked awaiting the conversion process. When one batch of car was completed, Ford would drop off a new batch and pick up the finished units.
In 1968 Ford introduced a high performance variant of the Mercury Cougar called the XR7-G that was advertised by Dan Gurney (the G in XR7-G). Of the 619 XR7-Gs produced, 431 of them were sold with sunroofs that were installed by American Sunroof.
American also installed an unknown number of sunroofs on regular XR7s and a small number of roofs were supposedly installed on Mustangs, although documentation is lacking.
Prechter also installed sunroofs on 1967-1968 Ford Thunderbirds although where they were installed is the subject of some debate. Although it would make sense that the roofs were fitted at the Southfield Road plant in Ecorse, one industry source claims the work was done across town at a different facility on Plymouth Ave. (Rd.?)
After Heinz moved to Detroit, his interest in the southern California operations waned and he turned the entire operation over to his brother Christian. Now known as American Sunroof Corporation, West Coast, Christian Prechter still operates out of 7322 Quinby St. with a satellite branch at 9240 Dowdy Dr. in San Diego, CA. At on time or another, Christian Prechter owned and operated warehouses in Van Nuys at 7834 Sepulveda Blvd. and West Los Angeles at 1862 S. La Cienega Blvd.
American Sunroof’s Northern California branch moved from downtown San Francisco to larger quarters in South San Francisco at 263 S. Maple Ave. in the late 1960s. Prechter’s exact involvement in the San Francisco branch after his move to Detroit is unknown, however the firm continued to install Golde sunroofs and also sold ASC’s Custom Craft accessories through 1977 when they moved to 372 Shaw Rd.
By 1970 American Sunroof Corp. had combined all of its Detroit operations at one plant which was located at 13500 Reeck Rd, in Southgate, Michigan. Also new was ASC Custom Craft Inc., a new subsidiary that specialized in producing aftermarket styling parts that could turn an early to mid 1970s Cadillac or Lincoln into a neo-classic, or what was more commonly referred to as a ‘pimpmobile’.
ASC Custom Craft offered “..a complete line of luxury customizing and classic automotive finery for the personalization of your customer’s cars. I am sure that you are finding that in recent years more and more car buyers are interested in adding to their cars these special touches of excitement and luxury.”
Available products included custom grills, ‘Superfly’ headlight trim, custom hood ornaments, padded half landau roofs, landau irons, fender skirts, rear deck lids with faux spare tire hump, rear deck trim, color keyed wheelcovers, oval or formal continental windows, a dash-mounted 3” television and special interior trim.
Custom Craft’s products were marketed directly to Cadillac dealers, whereby desired components could be ordered by the dealers and installed on site. Custom Craft also offered a full installation program whereby the entire customization process could be completed in their Southgate workshop.
Their Cadillac Eldorado conversions were the most popular however they offered styling products for the Fleetwood/Deville as well as a complete line developed for the Lincoln Mark and Ford Thunderbird. Many of the products could be fitted to other vehicles, and the firm produced a handful of full customs built on customer-supplied Buicks, Oldsmobiles and Pontiacs.
ASC Custom Craft offered a full styling conversion of the Eldorado which was called the el Deora. The changes were largely cosmetic and consisted of a reworked grill, a heavily padded landau roof that extended into the top of the doors and a faux spare tire hump mounted on the decklid. At least one stretched FWD el Deora was built using a 1974 Eldorado.
They also offered a slightly stretched Fleetwood limousine which was marketed as the Fleetwood Talisman El Deora. The Talisman was a highly optioned Fleetwood that was offered by Cadillac in the mid 70s. ASC Custom Craft introduced a line of Cadillac station wagons that were built on the rear-wheel-drive Deville chassis and are known to have built a number of wagons using Eldorados, one of which was owned by recording star Glen Campbell.
ASC’s wagons were built using the back half of salvaged GM clamshell station wagons that were attached to new 4-door Devilles and Fleetwoods at the C-pillars. Most of the Eldorados were attached at the B-pillar although a few, including Glen Campbell’s, were attached at the C-pillar and included the small Eldorado rear quarter windows. The 4-door wagons resembled the full-sized Oldsmobile and Buick Wagons and were quite successful. The Eldorado-based wagons looked awkward from day one and very few were built. During the early- to mid-70s ASC exported over 100 Cadillac wagons and specially outfitted Fleetwood limousines to Saudi Arabia.
Mike Alexander, one of the famous Detroit-based Alexander Bros. car customizers, went to work for ASC in December of 1970. As Alexander was a skilled metal and fiberglass fabricator, he was placed in charge of ASC Custom Craft’s body shop. Alexander personally supervised the production of the firm’s wagons and stretched limousines, which explains the high level of craftsmanship that can be found on the remaining survivors. He remained with the firm through the late 90s and helped engineer the Cadillac Evoq’s folding hardtop which debuted at the 1999 Detroit Auto Show.
By 1974 American Sunroof was operating plants in Michigan, California and Georgia and had sales of $7 million.
Ford’s L. David Ash, who had earlier worked with George Barris on the 1964 Super Marauder showcar, later worked with Heinz C. Prechter on the development of the moonroof, which first appeared on the 1974 Lincoln Mark IV and Ford Thunderbird. Ford’s Don Kopka also worked on the combined ASC/Ford Motor Co. project whose name was coined by Lincoln-Mercury’s advertising agency.
Although it was a big deal at the time, the moonroof was simply an oversized sunroof made from smoked tempered glass that featured a reflective silver or gold mirror finish that helped to keep interior temperatures to a minimum. Moonroof-equipped vehicles also included an insulated headliner panel that could be slid over the glass to keep direct sunlight out of the passenger compartment. The moonroof’s mountings, cable drive and electrical components were all based on Golde patents modified by ASC to better deal with the increased size and mass of the glass.
By the late 70s, Custom Craft’s earning were dwarfed by those of their parent who were now supplying sunroof kits to most of the country’s automotive manufacturers. The roofs had become so popular that their installation was now incorporated into each respective manufacturer’s assembly lines using kits supplied by ASC.
In May of 1976 ASC built a small run of 32 commemorative Ford Thunderbirds for a Charleston, West Virginia and Cincinnati/Dayton Ohio dealer group that included a simulated spare tire mounted into the decklid. The moonroof-equipped cars were all painted silver and fitted with padded black landau roofs and a matching leather interior.
The T-Top was based on a novel roof that first appeared as an option on the 1961 Triumph TR-4. Triumph offered a roof that include a fixed rear window with an integral roll bar that included a center section that could be removed for open air motoring. The top went largely unnoticed until it was adopted by Porsche and introduced on the 1966 Porsche 911/912 Targa.
General Motors borrowed the basic elements of the design and incorporated into their split-Targa T-top which debuted on the 1968 Chevrolet Corvette. GM’s T-Tops offered a center reinforcement bar not found on the Porsche that significantly strengthened the car’s roof and helped eliminate potential rattles and door alignment problems. The resulting two-piece roof was also significantly lighter than the Porsche’s one-piece design and could be easily installed by a single person.
GM later introduced the first production OEM transparent T-top on the 1977 Chevrolet Corvette, although they had been available from third party manufacturers as early as 1973. It’s unknown as to which firm introduced them first, but Hurst, Cars & Concepts and American Hatch (unrelated to ASC) all claim to have introduced them in 1973.
The Hurst Hatch debuted on the 1975 Hurst-Olds 442 although they had been available as a dealer-installed accessory since 1973. According to a number of sources, the Hurst Hatches were distributed by Hurst Performance Inc. but were actually built and engineered by ASC although ASC has never included them on their lengthy list of achievements. The Hurst T-tops were far better engineered than their competitors units, so it’s entirely possible that ASC had something to do with them, but documentation is lacking.
ASC’s first documented T-tops appeared on the Mustang II. Although the Ford Mustang II was available with a choice of sunroofs (the Ghia even offered a moonroof) starting in 1976, it could be ordered from the factory with T-tops which were engineered for Ford by ASC.
The tinted and tempered smoked glass panels were easily removed and could be stored in protective vinyl pouches when not in use. The tops were engineered specifically for the 3-door fastbacks and were not available on the 2-door Ghia/notchback. Ford also offered ASC-engineered T-tops on the downsized 1977 Mercury Cougar as well as its new downsized cousin, the 1977 Ford Thunderbird.
The T-tops found on the Dodge Magnum/Mirada and Chrysler Cordoba and Imperial were also developed and manufactured by ASC. At about the same time ASC revived the simulated convertible top, and although they took credit for it, the design dates back to the early-1920s when it was called the faux cabriolet.
In conjunction with Oldsmobile, ASC developed the 1976 Toronado XSR showcar, the first car to include a power-operated T-top. 1977 was the first year that General Motors was not offering a convertible and the power T-top was envisioned to take its place. Oldsmobile had planned on production 2,000 examples of the car during the 1977 model year, and even included the model in its 1977 large car brochure (pp 22-23), but the project was scrapped when it was determined that the roofs were too complicated to built in large numbers.
ASC tried selling the project to Cadillac, producing a White 1977 Eldorado that was displayed at the 1978 Detroit Auto Show, but the project was nixed as they were ramping up for the all-new 1979 Eldorado. A second Eldorado, a 1978 Biarritz, was later built for Heinz C. Prechter as his daily driver. Amazingly all three cars still exist, Joseph Bortz owns the Eldorado and the Toronado, now in New Jersey, appeared in a recent issue of Collectible Automobile, an the Prechter Eldorado is currently owned by an Arizona collector.
In 1981 ASC was hired by Buick to create two Union 76-badged Buick Regal NASCAR Pace Cars. They took a T-top equipped 1981 Buick Regal coupe and cut off the roof at the B pillar and replaced it with an 8-inch wide roll bar. Behind it, a totally removable landaulet top was fitted between the new roll bar and rear deck lid that when removed gave the occupants of the car an uninterrupted view of the racing field. The interior was fitted with color coordinated Recaro seats and door panels and the silver and maroon car’s lower body sides bore a graduated stripe that started off with increasingly darker shades of orange, maroon and brown.
Although ASC built the two actual 1981 Union 76 Buick Regal Pace Cars, the production version of that vehicle, the 1981 Buick Regal Pace Car, was assembled by Cars & Concepts of Auburn Hills, Michigan, not ASC.
The Iranian hostage crisis that commenced in 1979 eventually resulted in a sharp drop in domestic auto sales which forced ASC to lay off a large number of workers. Although ASC’s various divisions had employed as many as 2,300 during the late 1970s, by mid 1981, that number had plummeted to 500.
Prechter searched for additional streams of revenue as well as new services and products lines, and came up with an ingenious scheme; he would try to resurrect the convertible.
The last convertible built in Detroit (except for the Corvette) rolled off a Cadillac assembly line in 1976. Prechter realized that even if convertibles sold well, Detroit’s new robotic assembly lines would never be able to handle the specialty work. The financial opportunities were endless, not only would he supply the convertible top and electrics, the complicated installation process would need to be done at ASC. The project was simple - getting a manufacturer to commit to it would be the only problem.
1982 would prove to be a most important year for American Sunroof, Prechter reorganized the company and shortened its name to ASC, Incorporated, and Buick debuted the ASC-built 1982 Riviera Convertible.
Prechter had chosen the front-wheel-drive Buick Riviera as it classic good looks made it an attractive convertible. Costs were worked out to the last penny, and Buick brass approved the car for a limited run during the 1982 model year. Despite it’s nearly $30,000 price tag, the car sold well and production at ASC’s Linden, New Jersey plant was extended through 1985.
Other GM divisions took notice and introduced their own ASC-built convertibles in 1983. Pontiac’s version appeared on its budget-priced Sunbird as did Chevrolet on its similarly-priced Cavalier. Both cars were built at an ASC plant in Lordstown, Ohio. Cadillac began offering their ASC-built Eldorado Convertible in 1984, although the convertible was dropped in 1986 (as was the Riviera Convertible) when both cars were replaced by noticeably smaller vehicles.
Even foreign automakers were impressed with the Riviera convertible, and in 1983, ASC was commissioned to create a soft-top, four-seat Saab 900 Convertible based on the Swedish automaker’s two-door sedan. The pearl white prototype was unveiled at the 1983 Frankfurt Auto Show and was promptly slated for production, which commenced in late 1985. ASC’s involvement was limited to the engineering of the top which was built at Valmet Automotive’s Uusikaupunki, Finland assembly plant.
In 1984 Prechter established a factory in the Los Angeles suburb of Rancho Dominguez (Long Beach) to convert Toyota Celica Coupes into Convertibles. The car was produced, although not in every model year through 1999 when the Celica was dropped. Celica Convertibles were produced in: 1984-85, 1987-89, 1991-93 and finally 1995-1999. Starting in 2000, ASC’s Kitchener, Ontario plant began producing the Solara convertible, which continues to be built up to this day. The manual top of the short-lived 1997 Paseo Convertible was also installed at ASC’s Rancho Domingo facility.
ASC also built and engineered the reintroduced 1983 Mustang convertible, but due to a higher than expected demand, Ford took over its manufacture in 1984. A longer-lived Ford-ASC project was the ASC/McLaren Mercury Capri and Ford Mustang which debuted in 1984.
The McLaren name on the car was misleading, as the car didn’t include any engine modifications, however it did include a number of components that increased its aerodynamics and handling. Although the Livonia, Michigan-based McLaren Performance Technologies was started by Bruce McLaren to build engines and other parts for his Can-Am cars, the American division became an independent organization, separate from the Britain-based McLaren Engineering that builds the McLaren automobiles and F1 cars.
ASC/McLarens featured special wheels, shocks, springs, valances, spoilers, ground effects, headlight/taillight covers, trim and badging. The car was built as a Capri from 1984-1986, but when Ford killed Mercury’s Fox platform, production shifted over to the Mustang. All of the Mustang-based ASC/McLarens were convertibles as were two thirds of the Capris. Some of the remaining Capri hatchbacks were fitted with ASC T-tops, which were also available on regular Capris and Mustangs.
According to ASC/McLaren historian Sandy Block, from 1987-1990, 1,806 Ford Mustang-based ASC/McLarens were constructed. A dozen 1990 2-Seat Roadsters with red ("Scarlet") interiors were dash-plaqued (#1900-1911) in sequence and set aside to be made into "Silver Anniversary Editions" at the end of the 1990 regular production run to help commemorate ASC’s 25th anniversary.
However only two such cars were actually built - Block owns one (#1904), and the other (#1907) is owned by a Tampa, Florida collector. The remaining 10 dash-plaqued Silver Anniversary Editions (#1900, 1901, 1902, 1903, 1905, 1906, 1908, 1909, 1910 and 1911) were eventually painted either red, white or black and finished as regular 1990 ASC/McLarens.
Between 1984 and 1986, 874 Capri-based ASC/McLarens were built, 322 of them hatchbacks and 552 convertibles. There were three different Capri-based hatchbacks, the standard version, of which there were 245 examples, plus 1985’s Grand Prix edition (30 built) and 1986’s budget-priced Euro-Coupe (47 built). An unknown number of the coupes were fitted with ASC T-tops. A surprising number of ASC/McLarens were built considering its considerable price tag, which topped $20,000 in 1984.
ASC built the much maligned Chrysler K-car executive sedan and limousines that were built using donor LeBaron coupes between 1984 and 1987. Unlike most of ASC’s stretched vehicles, the Chryslers were built using Chrysler-approved jigs and the cars were fully warranted by the automaker. The executive sedan was built in very small numbers and was dropped after 1985, however the limousine was slightly more popular with over 500 examples produced between 1984 and 1987.
When American Motors decided to produce a convertible version of the Renault Alliance in 1985, ASC was awarded the contract. The car survived into 1987 when it was joined by the high-performance Renault GTA convertible. Production ended later that year when American Motors was acquired by Chrysler.
In 1985 ASC strengthened their long association with General Motors when they were selected to build the 1986-1996 Corvette Convertible. A new plant was constructed at 200 Tobacco Rd, in Bowling Green, Kentucky, three miles west of the main Corvette Assembly plant. Corvettes slated to receive convertible tops are shipped to the ASC plant where the tops are installed and then tested for leaks.
ASC has also built a number of Corvette show cars including the 1990 Corvette ZR-1 Convertible that featured a radically raked windshield and chopped convertible top that was slightly reminiscent of the chopped top found on Porsche Speedsters. The red Corvette LT1 Spyder prototype that debuted at the 1993 North American International Automobile Show was also built by ASC.
In 1987, ASC bought Aeromotive Systems Co., a leading supplier of heavy truck interior systems whose customers included Freightliner, Volvo and PACCAR.
McLaren and ASC teamed up once more in 1987 when they built the legendary Buick GNX. The all-black Grand National-based coupes featured a turbocharged 6-cylinder that had been developed by McLaren Engines. The GNX was only built during 1987 with a total production of 547. Two GNX police car prototypes were also built, but no orders materialized, perhaps the $30,000 price tag kept law enforcement agencies at bay.
Pontiac debuted their own ASC/McLaren supercar, the Turbo Grand Prix, in 1988. While the Buick GNXs were built on a dated GM g-body rear-wheel drive platform, the 1988-1990 Turbo GP (2-dr) and Turbo GP/STE (4-dr available in 1990 only) were built on GM’s new w-body front-wheel-drive platform.
The Turbos included a number of novel accessories including a heads-up speedometer display, ABS brakes, and the Turbo STE version included 8-way pneumatic bucket seats with adjustable lumbar supports which were the most comfortable seats ever offered by GM. The car’s 300hp turbocharged V6 was developed by McLaren and featured a long list of components not found on stock 3.1 liter Grand Prixs. Pontiac dropped the turbos in 1991, replacing them with the new Grand Prix GTP which featured a new 3.4 liter twin cam V6.
Dodge’s 1989-1990 Dakota Sport Convertibles and 1990 Dakota SE Convertibles were transformed by ASC. The Dakota Convertible was the first production convertible pickup that had been built since 1931. The truck was built using 2-door Dakotas that had been built by Dodge in its Warren, Michigan assembly plant. The ASC conversion included and integral roll bar and special graphics and were available with either 2wd or 4wd drivetrains, but otherwise the truck remained stock. 2,842 of the vehicles were built in 1989, but production fell to half that number, 909 in 1990. The vehicle’s slow sales killed the project in 1991, although an additional 8 vehicles may have been produced in 1991.
Another lucrative GM contract commenced in 1987 when ASC won a contract to build the Chevrolet Camaro Convertibles. T-top equipped coupes were sent to ASC where their tops were cut away and replaced by a new windshield header and ASC’s proven convertible top mechanism and rear deck assembly. Further bracing was installed in the vehicle’s rocker panels, floorpan, cowl and rear quarter panels, then the interior was buttoned up and sent on its way.
In 1987 ASC built the Firebird Suntour concept car for Pontiac. The silver car featured a unique one-piece windshield that flowed into the roof, eliminating the windshield header. ASC even managed to fit the car with a matching rail-to-rail retractable cantilevered sunroof that slid over the top of the car’s integral B-pillar/roll bar.
Pontiac became part of the ASC’s convertible program when their Firebird convertible was introduced in 1987. The arrangement continued through 1992 when the old F-body was replaced in 1993. The new convertible was ready within a few short months and production resumed in 1994. The last Camaro convertible was built in 2000, the final Firebird in 2002.
ASC also turned stock Pontiac Firebirds into Trans Am Ram Air WS6s from 1998-2002. Cars were shipped to ASC from Pontiac’s Ste. Therese, Quebec assembly plant where the fiberglass ram-air hoods and WS6 components were installed. Although production of the LS6 was initially slated at 6,500, the car proved so popular that close to 40,000 examples were built in the five years the car was offered. The other limited production 1998-2002 Firebird, the Firehawk was modified by Fred Hamburger’s SLP Engineering in Tom’s River, New Jersey, not ASC.
One important 1988 acquisition was the Pioneer Engineering and Manufacturing Co. and its sister company Troy Design Group. Both firms were heavily involved in auto design and engineering and they were instrumental in jump starting ASC's specialty vehicle manufacturing division which is now known as American Specialty Car. ASC’s engineering expertise was further strengthened in 1990 when they entered into a partnership with Modern Engineering of Warren, Michigan, a specialty vehicle design and engineering firm.
In 1988 ASC established a German subsidiary, Prechter GmbH, to manufacture convertibles for Porsche in Heilbronn, Germany. The deal was also tied to Prechter’s takeover of the long established German coachbuilder, Karosseriewerke Weinsberg GmbH.
Weinsberg translates as wine mountain and is the name of the city where Karisseriewerke Weinsberg orginated. Founded in 1912 by Gustav Alto and William Shoemaker, the firm produced horse-drawn carriages and wagons for the German military during the First World War. After the war they continued building wagons, many of which were sent to France as reparations for the conflict.
Prior to the War they had built a handful of automobile bodies, but starting in 1920, they began building bodies for NSU, and by the end of the decade, they counted Auto Union, BMW, Citroën, Daimler-Benz, Ford, Magrus Opel and Wanderer amongst their customers. In 1930 they became FIAT’s German coachbuilder of record and began to recieve a large number of orders from the Italian automaker, included a large order of 1500 taxis (Kraftdroschken) for use in Berlin.
By 1937 the factory employed 699 persons and had sales in excess of 3.5 million Deutche Marks. The following year, 1938, they became a wholly-owned subsidiary of FIAT. The began to manufacture bodies for the FIAT Topolino which was manufactured by another FIAT subsidiary, NSU, in nearby Heilbronn. During the war they built wing assemblies for the Messerschmitt ME-410 and ME-422 as well as bodies for German jeeps and light vehicles.
Following the war they re-established a working relationship with FIAT/NSU and added new customers who included Gutbrod, Porsche and Büssing. In the 1950s Weinsberg branched out into the manufacture of sunroofs which soon became a specialty.
Today they’re mainly remembered for their FIAT 238-based Weinsberg Caravans which competed against the Volkswagen Type II campers and were manufactured from 1969 to 1992. They also manufactured a line of police vans, hearses and ambulances that were based on the caravan.
FIAT decided to sell their German holdings in 1970 and Karosseriewerke Weinsberg and two related firms in Heilbronn were sold to a group of German investors. The factory continued to produce and install sunroofs for Porsche and also began producing light commercial vehicles using FIAT, Mercedes and Volkswagen chassis.
In 1983 the firm’s 550 workers moved into a newly constructed factory. Heinz C. Prechter had always had an appreciation for Porsches and had owned a late 50s Porsche 365 for a number of years.
In March of 1988 Prechter GmbH, the German subsidiary of ASC, purchased a 50% interest in the firm and started producing Porsche 944S2 convertibles in a newly constructed Karosseriewerke Weinsberg plant in Heilbron, West Germany. A one-off 4-door Porsche 928 sedan prototype built in 1986 by AMG was presented by Porsche to Prechter following the opening of his new Heilbronn factory.
The following year Prechter purchased the remaining half of Karosseriewerke Weinsberg, which was now a wholly-owned subsidiary of Prechter GmbH/ASC. Production of the Porsche convertibles continued when the 944S2 became the 968 in 1992 however the plant was closed when Porsche stopped building the car in late 1995. By that time Prechter had already sold ASC’s Weinsberg-based operations to the Knaus Tabbert Group GmbH.
In 1989 ASC established a branch in Spain where it produced the Volkswagen Golf-based Ibiza Convertible for the Spanish automaker SEAT. The following year ASC was awarded a contract to convert the Infiniti M30 Coupe into a convertible. From 1991-1992 an estimated 2500 M30 convertibles were built by ASC at their Rancho Dominguez, (Long Beach) California assembly plant.
Although some articles have inferred that ASC built the GMC Syclone/Typhoon sports trucks, they were actually built by Production Automotive Services (PAS), of Troy, Michigan. However, ASC did built a special run of 10 T-top-equipped Sonoma-based Syclone pickups for Larry Shinoda in 1991. The bright-red trucks are known as Marlboro Syclones and were commissioned by Philip Morris for a Marlboro Cigarette sweepstakes where they were offered as the grand prize. They 10 red Syclones had T-tops, Recaro seats, Boyd Coddington wheels, a retractable rear window, a CD changer, and a Guidon fiberglass tonneau cover.
From 1990 to 1993 ASC produced the Dodge Shadow convertible using Shadow 2-door sedans. Only available in the Highline and ES trim, the inexpensive car was popular, in 1991 alone almost 45,000 were produced. The car could also be ordered in ES trim with a turbocharged 2.5 liter engine although few were sold.
From 1992-1995 ASC supplied Rover with convertible tops for the first generation Rover Metro (former Austin Metro), which was the smallest production car that ASC had ever been involved with. Although the car was a two-door it was built using the stouter Metro 5-door platform. It debuted at the Berlin Motor Show in late 1992, and featured a fully-lined manually-operated black top. When Rover launched the face-lifted Metro convertible in late 1995, it featured a new grey-colored, electrically operated top that was not built by ASC.
In 1992 ASC was awarded another Nissan contract, this time for the convertible edition of the Nissan 240 SX. Most ASC convertible conversions were built using existing coupes, however the 240 SX convertible was different. Most of the required bracing and unibody reinforcements were already installed before Nissan shipped the car to ASC’s Rancho Dominguez assembly plant. The car proved popular and 8,320 examples were built between 1992 and 1994.
The 240sx contract led to another Nissan conversion and from 1993-1996 ASC built the 300ZX convertible, and even developed a retractable hardtop version for the automaker, which was shown at the 1991 Geneva Auto Salon, but they weren’t interested in the design. However their competitor, Mitsubishi, was and from 1995-1997 ASC built the limited production 3000 GT Spyder at their Rancho Dominguez assembly plant.
A little over 1,000 (1,034) Mitsubishi 3000 GT Spyders were built at ASC’s Rancho Dominguez assembly plant from 1995-1997. As did Nissan on the 240 and 300 ZX, Mitsubishi installed some of the needed bracing and unibody supports in Japan prior to shipment to ASC, however, the car was sent with its coupe roof intact.
ASC removed the roof with a plasma cutter and in its place installed a Mike Alexander-engineered retractable SMC (sheet-molded-compound) hardtop assembly which was operated by two computer controlled hydraulic cylinders located in the trunk. It took a short 35 seconds to completely lower the top whose computer included software that halted the operation if the top met a foreign object such as a human head, hand, golf club or piece of luggage.
The SMC top, tonneau cover and its related hydraulic and electrical components added 280lbs to the weight of a FWD 3000 GT coupe and was significantly lighter and simpler than the system used by Mercedes-Benz on their SL roadster. The 3000 GT was available in both front-wheel-drive and Mitsubishi’s VR4 all-wheel-drive system, and when fully optioned stickered for $65,000.
ASC was responsible for the convertible Buick Reatta which debuted in 1990, two years after the Reatta coupe debuted in 1988. The car was built using a shortened Riviera floorpan and was largely assembled by hand at GM’s Lansing, Michigan Craft Center.
The ASC-designed top was raised by hand although it feature a power assisted pull-down at the rear. The top’s base was wider than the opening it disappeared into and it required an extensive amount of testing to get it to work, which delayed its appearance by almost a year. The convertible Reatta was rare when its was new, of the 21,751 Reattas produced, only 2437 were convertibles.
When production of the Reatta ceased in 1991 GM used the Craft Center for pre-production and testing of the Impact/EV1. However plans for mass production of the electric vehicle were eventually scrapped, and in December 1993 ASC and General Motors entered into a 50/50 partnership called GENASYS to build the next-generation Chevrolet Cavalier and Pontiac Sunfire convertibles in the idle Lansing facility.
Starting in 2000, the final assembly of the limited production Cadillac Eldorado was moved to the plant. When the Eldorado project was shut down the Craft Center prepared for the manufacture of another ASC first, the Chevrolet SSR.
In 2003 ASC revisited the convertible pickup, although this time their customer was Chevrolet, and the vehicle was the SSR Sports Truck. The world’s first retractable hardtop pickup, the 400hp SSR (Super Sport Roadster) SSR won a 2003 Chrysler Group Gold Award and received another Gold Award in the 2004 Industrial Design Excellence Award competition.
The 2-seat 6.0-liter V8-powered sport truck was built on a shortened Trailblazer chassis and featured an innovative electrically-operated retractable hardtop that could be stowed in a well behind the seats.
In a twist on the firm’s normal assembly procedure, the SSR’s body and roof were assembled offsite by ASC then shipped to the Craft Center where it met up with the completed chassis. The $35,000 truck was first delivered in mid-2003 and ended production in 2006 after just under 25,000 units had been sold. A specially outfitted West Coast edition debuted in 2005 that was built in conjunction with the So-Cal Speed Shop for distribution to Southern California Chevrolet dealers.
In 1992 ASC constructed a new 115,000 square foot plant in Columbus, Ohio designed to house all of the firm's sunroof operations. The plant was located near Honda’s Marysville, Ohio plant as ASC had won a contract to supply the firm with sunroofs for the next generation Honda Accord. The plant also furnished roofs for a number of Chrysler Corporation products and displayed a special sunroof-equipped LHS-based Chrysler 300 at the 1994 North American International Auto Show.
In January 1995, Heinz Prechter turned over the reigns of ASC to Donald Barefoot, the firm’s newly hired chief operating officer. Barefoot proceeded to re-organized the firm, which had recently lost a number of lucrative contracts, specifically the contracts for the next generation Corvette and Saab 900 convertibles. ASC’s share of the OEM sunroof market was also slipping, and in the mid 90s they lost the sunroof contracts for the US-built Toyota Camry to their chief competitor.
However ASC’s share of the convertible top market was increasing and in 1995 they controlled 25% of the domestic market. Barefoot also gave the firm’s four divisions; American Sunroof, ASC Convertible Systems, Automobile Specialty, and Aeromotive Systems, more autonomy.
In 1997 Barefoot resigned and a former General Electric executive named Lawrence Doyle took his place. Doyle combined the firm’s convertible and sunroof business into a single entity and created a new one, Aeromotive Services, to design prototypes and production convertibles.
In 1997 ASC lost another sunroof customer when Chrysler awarded the sunroof contract for the Chrysler Cirrus and Dodge Stratus to Webasto Sunroofs. The Columbus plant was seriously underutilized so later that year ASC entered into a joint venture with the Honda’s Japanese sunroof supplier Yachiyo Industry Co., Ltd., creating ASC-Yachiyo Manufacturing Ltd. (AYM).
In 1997 ASC sold a 50% share in Aeromotive Systems to Minneapolis-based Heavy Duty Holdings (HDH), a firm owned by Hidden Creek Partners LLC, a Minneapolis, Minnesota-based automotive holding company founded by Sankey A. (Tony) Johnson and Scott D. Rued. The resulting firm, renamed Trim Systems LLC, was headquartered in Columbus, Ohio, and owned manufacturing facilities in Ohio, Washington, North Carolina and Virginia.
Prechter’s holdings weren’t limited to ASC, in the early 80s, Prechter went on a newspaper buying spree, purchasing 12 regional newspapers which were organized into Heritage Media. His extensive real estate holdings were managed by another firm called Heritage Development. A third firm, Heritage Networks, managed his portfolio and a fourth, Heritage Beef and Cattle, managed his 10,000 acre Texas cattle ranch.
In 1997 Prechter created Prechter Holdings to oversee all of his varied business interests. He and his wife Wally had previously founded the World Heritage Foundation, a charitable organization created to promote the revitalization of Detroit’s Downriver community and German-American culture.
Although he didn’t realize it at the time, Prechter was indirectly responsible for the corporate marriage of Daimler-Benz and Chrysler Corp. While touring the North American International Auto Show in January 1997 Prechter introduced Robert Eaton, Chrysler’s chairman and CEO, to Jurgen Schrempp, Daimler-Benz’s Chairman and CEO.
ASC’s Aeromotive Services built the Lexus RX 300 Sport Luxury Vehicle (SLV) concept that debuted at the 1997 Chicago International Auto Show. The SLV was one of the first automobile-based ‘crossovers’ that combined the characteristics of an SUV, wagon, and sedan in a single package.
In conjunction with Detroit’s Center for Creative Studies ASC built the student-designed TekQua Concept for exhibition at the January 1998 North American International Auto Show. Based on a Dodge Dakota extended-cab pick up with the roof cut off, the Tekqua was designed with an aquatic theme and featured a Neoprene interior.
A Warren, Michigan based design and engineering center was founded in 1998 and the following year ASC built a plant in Kitchener, Ontario, Canada to build the new Toyota Solara convertible. Another new plant was built in Bloomington, Illinois that produced convertible tops for the next generation Mitsubishi Eclipse.
ASC and the Center for Creative Studies teamed up again to create the BMW Z3 roadster-based Ohm show car which was exhibited at the January 2000 North American International Auto Show. The Ohm included a digitally-enhanced sound system; leather seats and trim in a variety of unique colors and designs; and a specially- patterned, UV-illuminated floor design.
The 1999 Cadillac Evoq showcar featured a retractable hardtop that had been fabricated by Mike Alexander, a long time ASC fabricator who had gained some notoriety in the 1960s when he and his brother ran a custom body shop in Detroit. The Corvette-derived Evoq was also Cadillac’s first real sportscar and served as the basis for the Cadillac XLR which entered into production in 2004.
ASC created the 1999 Buick Cielo Concept which was a showcase for their sliding roof panel technology. The Cielo - sky in Spanish - featured two permanent roof rails run fore and aft on each side featuring 3 sliding opaque glass panels within the rails. The driver, using the voice command "Open Roof," can turn a sedan into a convertible in a few seconds. The rear window was also voice-activated and could be raised or lowered independently, or in concert with the roof. The car also included power-operated suicide doors and recessed rocker panels, sill plates and underbody extensions to allow easy access for the car’s inhabitants.
Another memorable ASC showcar was the 2000 Buick LaCrosse prototype. The car’s styling included a number of historic Buick-related cues including a vertical-barred grill, real fender portholes, suicide doors and a side-opening hood. The front end recalled the 1995-1999 Riviera, and the rear end included a cargo area that was accessible via a disappearing tailgate whose retractable roof and rear window slid forward creating an open-topped load area, a design that was later used in the short-lived 2003-2005 GMC Envoy XUV.
The LaCrosse’s interior was void of any recognizable dials or switches, most accessories were operated by a voice-assisted console mounted trackball who relayed data to the passengers via dual heads-up displays, one for the driver, one for the passenger. The car featured familiar driving controls and the unusual bucket seats or ‘club chairs’ included motorized footrests for every passenger.
The ASC-built Chevrolet Triax concept was unveiled at the October 1999 Tokyo Motor Show. The five-passenger urban activity vehicle was built in conjunction with Suzuki and its multiple-propulsion architecture allowed the vehicle to be powered by hybrid, internal combustion, or all-electric propulsion systems.
ASC opened an advanced convertible design and engineering studio in Munich, Bavaria in 2000, and a new ASC subsidiary, ASC Vehicle Technologies, built a plant in Oak Park, Michigan in 2001 to manufacture short runs of cars for its various customers.
In 2001 ASC Holdings created a partnership, ASC Exterior Technologies, with Kojaian Holdings to take over JPE, Inc., a bankrupt East Tawas, Michigan automotive supplier. JPE controlled three operating subsidiaries; Plastic Trim, Inc. of Beaver Creek, Ohio; Starboard Industries, Inc. of East Tawas, Michigan - both exterior auto trim suppliers - and Dayton Parts Inc., an aftermarket supplier of heavy truck suspension and brake systems located in Harrisburg, Pennsylvania.
Many of Heinz C. Prechter’s friends and associates were unaware the he had suffered from intermittent bouts of depression for most of his adult life. He had been undergoing treatment for the illness for a number of years at the University of Michigan's Depression Center and had managed to keep his condition a secret to all but his family and handful of close friends.
On July 6, 2001, Prechter's wife Wally discover his body hanging in a guest house on their Grosse Ile Township estate, he was only 59.
Prechter had long been a friend of the Bush family and was an important fundraiser for the Republican Party. President George W. Bush issued a press release shortly after Prechter’s suicide stating: "Laura and I were saddened to hear of the death of Heinz Prechter. He will be missed. He was a great friend of ours as well as the entire Bush family. He was an honorable and loyal man. Our thoughts and prayers are with his family during this very difficult time."
Prechter was survived by his wife Waltraud (Wally) and two children Paul and Stephanie. Prechter had planned on selling Prechter Holdings (ASC’s parent) prior to his death and in May of 2002 it was acquired by Jay Alix's Questor Management Co. LLC of Southfield, Michigan.
Soon afterwards, Wally Prechter established the Heinz C. Prechter Bipolar Research Fund at the University of Michigan.
Prechter had previously been named the Harvard Business Club’s Entrepreneur of the Year in 1979, and was later named Michigan’s Industrialist of the Year (1986), World Trader of the Year (1987), Northwood University’s Outstanding Business Leader (1988) and Crain’s Detroit Business Newsmaker of the Year (also in 1988). He was also a vocal proponent of NAFTA and helped the US Commerce Dept. lay the groundwork to ensure its success.
In September of 2002, Questor Management announced that Paul Wilbur, a former Daimler-Chrysler senior executive would become the ASC’s new CEO.
At the November, 2002 SEMA trade show in Las Vegas, ASC introduced a number of new prototypes and show cars. The first was the Chrysler PT Cruiser Big Sky, an all-wheel-drive PT fitted with an innovative five-panel glass roof system and a unique ground effects package.
Also exhibited was the Saturn ION QC/T, a turbocharged Saturn ION Quad Coupe that featured a composite sport hood with functional scoop, unique front and rear chin spoilers, rocker moldings, and spoiler stanchions. Saturn added carbon fiber roof rails.
The Mitsubishi Stage-1 Eclipse was built in conjunction with Mitsubishi, and included exterior appearance enhancements such as a blackout roof and rear spoiler, unique front and side grille inserts, and brushed aluminum door levers and aluminum fuel-filler cap. The sport image was carried into the interior with carbon-fiber accents and a custom black and red leather interior.
Also on display were a group of five Pontiac GXP show vehicles, the Pontiac Sunfire GXP, Pontiac Grand Am GXP, Pontiac Vibe GXP, Pontiac Bonneville GXP and the Pontiac Grand Prix GXP.
At the 2003 SEMA, ASC exhibited the Dodge Ram High Output 1500 Sportside, a high-performance pickup that featured an ASC-designed flared-fender composite cargo bed.
Starting in 1996 ASC’s Columbus, Ohio facility supplied BMW’s Spartanburg South Carolina plant with both soft and hardtops for the 1996-2002 Z3 and M-series roadster. The car was big success and over 250,000 examples were produced.
When planning commenced for the next generation Z roadster, which would be called the Z4, BMW wanted ASC, their American convertible supplier, and Edscha Cabrio-Verdecksysteme GmbH, their European convertible top partner, to work together on the new car’s roof system.
A limited partnership was formed between ASC and Edscha and a new plant constructed in Spartanburg to build the roof structures. The Z4’s top was principally designed at Edscha’s Hengersberg, Germany design center and the new Spartanburg roof plant hopes to produce over 300,000 tops over the course of the contract.
ASC and the Edscha Group of Remscheid, Germany are similar in size, and each firm employs between 3,500-4,000 employees and produce $500 million in annual sales.
In 2002, ASC and another European firm, Inalfa Roof Systems launched a joint venture called American Sunroof Inalfa. At the end of 2003, ASC quietly divested itself of its entire sunroof operations, which were purchased by Inalafa. In 2004 the Dutch Sunroof relocated its headquarters from the Netherlands to Wixom, Michigan.
The sale of ASC’s sunroof division coincided with the renaming of ASC to American Specialty Cars which was announced by CEO Paul Wilbur at the 2004 North American International Auto Show. Wilbur stated that the new identity served to illustrate the company’s new emphasis on the design, engineering and manufacturing of low-volume niche vehicles.
In 2004 ASC introduced the Dearborn Deuce Convertible, an all all-steel roadster body redesigned around a fully disappearing top assembly. Built in conjunction with Hot Rods & Horsepower, the car is based on a 1932 Ford roadster body that was redesigned to accommodate the hide-away top. The Deuce was the winner of two awards at the 2004 Specialty Equipment Manufacturers Association show—“Best-Engineered Product” and “Best Street-Rod Product” runner-up.
The cars are marketed by a Connecticut-based subsidiary of the Dearborn Mfg. Co., called Hot Rods & Horsepower LLC. The bodies are stamped out by Oakley Industries in Clinton Township, Michigan and then shipped to ASC’s Reeck Rd. assembly plant where they’re assembled, painted, trimmed and finally mated to a Downs Mfg.-built chassis fitted with a Ford crate motor. The finished vehicles, over 300-to-date, are then shipped to Hot Rods & Horsepower where they’re delivered to the customer.
In 2004 ASC, Chevy Trucks and The North Face - an outdoor equipment and apparel outfitter – teamed up for the Chevrolet TrailBlazer ‘TheNorth Face’ Edition, a limited-production SUV that included The North Face interior accents throughout the vehicle and two base camp duffel bags and down-insulated Nuptse blanket. ASC was also involved in the development of General Motors latest minivans, Saturn’s L Series, the Pontiac Sunfire H.O. 2.2 and Pontiac Vibe GTR.
In 2005 ASC produced a cosmetic ground effects and interior package for the Pontiac Grand Am SC/T. The car also included a supercharged 3.4-liter V6 and was shod with oversized 17” wheels and tires sourced from the Bonneville SSEI.
ASC’s Huntington Beach, California design studio produced two Suzuki Grand-Vitara-based showcars that debuted at the 2005 Las Vegas SEMA and 2006 NAIAS in Detroit - the ASC-Suzuki Wave and Dune. The Wave was billed as the world’s first UTV – ultimate tailgate vehicle – which featured a slide-out tailgate that contained a cooler and a grill. The Wave was also fitted with a convertible top, which made it the first 4-door convertible SUV.
The Dune was outfitted for the hardcore offroader, and featured 26 inches of ground clearance with the requisite oversize tires and fender flares. A unique under-car skidpad was smoothly integrated into the car’s front grille and the Dune was finished in a bright yellow, tying it in to Suzuki’s popular line of ATVs, two of which rode behind the vehicle on a matching yellow trailer.
Recent projects included the 2005 ASC Helios, a Chrysler 300-based convertible sedan, a design that was last seen on the 1967 Lincoln Continental. The Helios featured ASC’s latest convertible top, the Xpanse™ Convertible-Top System.
Another ASC showcar, the GTO Stinger, also debuted in 2005. Built using the Holden Monaro-based Pontiac GTO, the striking Yellow Fire pearl-colored vehicle utilized ground effects and body panels built using a number of new ASC composite processes.
ASC and McLaren teamed up for a third time when they released the 2006 ASC Diamondback Viper show car. The SRT10 coupe-based car was built to showcase ASC’s new OmniCarbon composite modeling process as well as McLaren Performance Technologies unique trumpeted air intakes, with individual port throttles that paid homage to McLaren’s Can-Am racecars. The 615hp Diamondback included a carbon fiber roof, deck lid, rockers, fascia inserts, body trim and a massive OmniCarbon hood that integrates seamlessly with the ten McLaren air intakes.
Also introduced in 2006 was ASC’s Hummer H3-based Cosmos concept which featured the firm’s new InfinVu fabric roof system. The InfinVu is a modern take on the large folding sun roofs that were found on 1950s-60s Volkswagen Type II transporter. Bi-directional, the between-the-roof-rails top slides either rearward toward the D-pillar or forward toward the A-pillar, or to any point in between, offering an infinite number of open-air iterations—for those in the rear of the vehicle as well as the front.
ASC has gone through a number of name changes in its 40+ year history. They were originally called the American Sunroof Corp., which became ASC in the early 1980s, and more recently (January 2004), American Specialty Cars, to reflect their new positioning as a builder of limited production vehicles and prototypes. In October of 2004, ASC’s founder, Heinz C. Prechter, was posthumously inducted into the Automotive Hall of Fame based on his numerous contributions to the American Automobile industry. On July 13, 2005 ASC celebrated the production of their 1 millionth convertible.
More recently ASC and Dodge worked together on the development of the Viper SRT 10 sportscars as well as appearance and body packages for the Neon and Caliber-based SRT-4s and Magnum and Charger-based SRT-8s. ASC is also responsible for the very attractive 2007 Mitsubishi Eclipse Spyder which is one of the few convertible conversions that look as good with the top up as down.
© 2004 Mark Theobald - Coachbuilt.com special thanks to Mike Pearson