More stories related to 2005 NAIAS DETROIT – A 4-door convertible has not been sold in the U.S. in more than 35 years, but supplier ASC Inc. believes the body style is overdue for a revival.

ASC debuts here at the 2005 North American International Auto Show its Helios concept car – a convertible sedan based on the Chrysler 300.

Although ASC says it has no deal with Chrysler Group to put the ragtop into production, the Southgate, MI-based supplier indicates the car could hit showrooms in two years. “If Chrysler doesn’t want it, we probably won’t go to the aftermarket (and convert stock hardtop sedans to convertibles),” says ASC President and CEO Paul Wilbur. “We would go to another OEM (with the program.)”

ASC’s patent-pending inward-folding “xpanse” convertible system folds the Helios’ 68-in. (173-cm) soft top into an 18-in. (46 cm) x 12-in (31 cm) area behind the rear seats in about 20 seconds.

ASC’s Helios concept

It steals a relatively minimal amount of trunk space, and the rear-seat room still is ample. “A hardtop is not possible,” says Wilbur. “We’d probably have to have four or five (roof) panels and it would completely occupy the trunk.”

ASC added structural enhancements at various locations, including new B-pillars and the floor pan. As a result, the Helios weighs about 300 lbs. (136 kg) more than the 300. But the supplier tried to keep modifications to a minimum. The car’s wheelbase and decklid are identical to the 300, for instance. “I think this car can be brought pretty affordably into the market,” says Wilbur.

Helios features four bucket seats, and a Sony XYZ multi-media entertainment system, which is removable from the vehicle.

ASC also unveils the Pontiac GTO Stinger and Chevy SSR Diamondback concepts. The GTO is juiced up from the stock 400 hp to an estimated 550 hp and features dual integrated hood scoops. The Diamondback is lowered 2-ins. (5-cm) from the production model and adds 100-hp, a fixed roof and dual side exhaust outlets.