Coy 'Cannonball' Buckman (David Carradine) and his blazing red Pontiac enter the Trans-America Grand Prix, an underground road race spanning the continent in which there are no rules, no speed limits and no heed for the law. En route, Buckman jockeys with an international ensemble of racers for a $100,000 purse. But there are none more important than Cade Redman (Bill McKinney), his direct competition for a guaranteed spot on the elite Modern Motors racing team.