Visions created at Cars & Concepts Inc., a $100 million-a-year special-vehicle manufacturer in Brighton, Mich., have almost invariably come rolling down the automotive assembly lines 6 to 18 months after inception. Invariably, that is, except for one project -- a De Lorean convertible.

Cars & Concepts chairman Richard Chrysler, who owns two De Loreans and whose company designed the logo for De Lorean, was convinced that John De Lorean would make a comeback, that the convertible he designed for the renegade auto man would become a reality. But given the present circumstances, with De Lorean facing trial on drug-trafficking charges and with the failure of the De Lorean Motor Co., the sketch of the ragtopped, convertible beauty Chrysler wanted to build probably will remain a pinup above a company drawing board.

The De Lorean convertible, however, is one of the few setbacks this six-year-old company has suffered. The company has successfully created a dual niche in the slumping auto world. First it built a name and reputation with T-Roofs, now patented in North America, Germany, and Japan, for the after-market trade. More recently, Cars & Concepts has been responsible for the rebirth of the convertible in the U.S. market.

The popular 1982 LeBaron convertible was born not at Chrysler Corp., but at Cars & Concepts, which put rag tops on some 19,000 K cars.

"Chrysler didn't know they wanted it when we walked in the door," says Richard Chrysler (no relation to Chrysler Corp.). "But by the time we walked out the door they were convinced they needed it."

Cars & Concepts saw wasted space in a Corvette and created a hatchback. It was a tough idea to sell to Chevrolet Motor Division, but sell it they did -- in the form of a 1982 Corvette collector's edition.

Nor was Ford Motor Co. immune to the company's pitch. Cars & Concepts is responsible for the 1983 Mustang convertible, with current-year orders projected at 37,000.

"We've never spent money on anything that hasn't sold," says Dave Draper, president. "It may not have sold as well as we would have liked, but we've never had an Edsel."

Both Chrysler, age 40, and Draper, 35, have had a lifetime love of automobiles. Chrysler started out as a professional drag racer before going to work for Hurst Performance Inc., a manufacturer of transmission controls. Draper got his start as a designer for General Motors Corp. and White Motor Research.

It was that love of cars that convinced the two that they could take advantage of the woes of America's domestic auto makers. They knew what they wanted in a car -- something that was uniquely theirs -- and were convinced that that is what the public wanted as well. Their formula for success was simple: Design a modification that makes a car a personal chariot, turn the idea into a production reality quickly, and insist on quality. "People want their cars to make a statement about themselves," Chrysler says. "Cars & Concepts helps them make that statement a little louder."

As Americans rekindled their love affair with the automobile, Cars & Concepts took off. Business tripled from 1980 to 1981 and again a year later. From a small company with a handful of employees working out of one unit in an office complex, the company has grown to employ 1,300; this year it will move into new corporate headquarters, a two-story office building across the street. Last year the company purchased Hurst Performance. Chrysler now owns the company for which he once worked.