Two street racingrs, the Driver (Taylor) and the Mechanic (Wilson) live on the road in their highly modified, primer-gray, 1955 Chevrolet 210 two-door sedan drag car and drift from town to town making their income by challenging local residents to impromptu drag races. As they drive east on Route 66 from Needles, California, they pick up the Girl (Bird), a female hitchhiker, in Flagstaff, Arizona when she gets into their car at a diner. Although the Driver develops a crush on the Girl, she sleeps with the Mechanic when the Driver goes out drinking one night. In New Mexico they begin to encounter another car driver, Pontiac GTO (Oates), on the highways. An atmosphere of hostility develops between the two parties. Although GTO is not an overt street racer, and, in fact, seems to know little about cars, a cross-country race to Washington, D.C. is suggested. The Driver proposes that the prize should be "Vehicle title," or legal ownership of the loser's car. Along the way, GTO picks up various hitchhikers, including an importuning homosexual hitchhiker (Harry Dean Stanton). When GTO's inexperience becomes apparent, he, the Driver and the Mechanic form an uneasy alliance; the Driver even drives with him for a while when GTO gets fatigued.