IN an economy as polymorphously diverse as America's, it seems unlikely that Harper's II Exotic Car Wash is the only one of its kind. But it could be. ''It's the only one I'm aware of,'' said Eddie Collins, who owns both the car wash and a nearby strip club.

Seven years ago, Mr. Collins, who drives a blue Corvette convertible and is partial to gold jewelry, was ''looking to make money during the day'' at his club. He considered selling used cars or getting a U-Haul franchise. Then the detailer who had worked on his own cars quit. A neon light bulb came on over his head: Why not open a topless car wash?

City officals resisted at first, but Mr. Collins took steps to preserve public decorum. A privacy fence eight feet high surrounds the entrance to the metal building behind the club, where women in G-strings wash the cars.

Business has been brisk, he said, averaging 25 cars a day -- more during the Greater Greensboro Open golf tournament or the A.C.C. basketball championships. The wash is open year-round; there are heaters in the building for the comfort of workers, who do not dress warmly.