The Trans-America Grand Prix is an illegal race held every year between Los Angeles, California (Santa Monica Pier) and New York City. Recently released from jail, where he was serving a sentence for killing a girl while driving drunk, racing driver Coy "Cannonball" Buckman (David Carradine) hopes to win the race and get his career back on track. Racing team Modern Motors have promised a contract to either him or his arch-rival Cade Redman (Bill McKinney) who is also in the race – the contract will go to whichever of them wins. Coy is still on probation and when his parole officer, Linda Maxwell (Veronica Hamel), with whom he is having an elaborate affair, discovers he will be crossing state lines in violation of his parole, she attempts to stop him, only to have him force her to accompany him on the race.