(FORTUNE Magazine) – In Days of Thunder, the Tom Cruise movie, the rags-to-riches car racing team owner played by Randy Quaid is modeled on J. R. ''Rick'' Hendrick, 41, of Charlotte, North Carolina. He's one of America's top independent car dealers (60,000 sold in 1989, for $683 million) and a real-life owner of four auto- racing teams. Hendrick, technical adviser on the movie set, is now gearing up for his next act. In October he will open three new dealerships for the Saturn, the long- awaited coupe that GM hopes will recapture the baby-boomer market from the Japanese. He'll be putting them in Charlotte, Charleston, and Raleigh. So confident is Hendrick of Saturn's success that he is converting his busiest dealerships -- now selling BMWs and Subarus, among foreign makes, and used American cars -- to handle only the compact GM models. An Arizona test drive made him a believer, he says. ''The Saturn felt as if it had a sports suspension. It was unbelievable.'' As important, he says, is the attitude of UAW workers he met at Saturn's Tennessee plant. ''It's not the old story about the guy who builds the car and doesn't care. It's the kind of enthusiasm you can't buy.'' Hendrick knows about building cars. He grew up on a Virginia farm and as a teenager bought clunkers, spruced them up with his father's help, and resold them. Back then he lacked financing and sold his his cars one at a time. Then his mother, a bank teller, taught him how to structure loans. He bought his first dealership at age 25, with $75,000 he borrowed from two banks -- one of them his mother's employer.