In Pixar’s Cars, Lightning McQueen competes in the Piston Cup race at the film’s climax.
The Piston Cup is the fictional stock-car racing championship that drives the movie’s opening and ending. The plot begins with a three-way tie between Lightning McQueen, Chick Hicks, and Strip “The King” Weathers. A final race is scheduled in California to determine the champion.
After accidentally ending up in Radiator Springs, McQueen learns cooperation and friendship from the town’s residents. He returns to racing with a new understanding of sportsmanship, while his former rivals continue to define the championship’s competitive stakes. The final race brings the story’s racing plot and personal growth together.
The name is a playful reference to real motorsport trophies, especially NASCAR’s former Winston Cup. It is not the Dinoco 400: that is the specific race depicted at the beginning of the film, while the Piston Cup is the championship itself.