In Pixar’s Cars, Lightning McQueen enters the Piston Cup race after being stranded in Radiator Springs.
The Piston Cup is the fictional stock-car racing championship at the center of the film’s story. McQueen is a talented but self-centered rookie who finishes a three-way tie in the season finale, forcing a tiebreaker race in California. While traveling there, he becomes separated from his transport truck and accidentally damages Radiator Springs’ main road.
The film’s racing world borrows recognizable features from American stock-car racing, including oval tracks, pit crews, sponsors, qualifying, and championship points. The Piston Cup itself is named after piston-engine technology, matching the movie’s vehicle-based setting.
A common mix-up is calling the championship the Dinoco 400. Dinoco is a major sponsor and the venue’s race is associated with the Dinoco brand, but the championship McQueen is pursuing is the Piston Cup. The later Cars films continue to use the Piston Cup as a major racing reference.