Cars features the Piston Cup championship race at Los Angeles International Speedway.
The race is the opening competitive set piece of the film and introduces Lightning McQueen, Chick Hicks, and The King as the three cars tied for the championship lead. A three-way tiebreaker is arranged after a disputed result leaves the title unresolved.
Lightning's decision to use only one set of tires contributes to the dramatic finish. A blowout leaves him tied with Chick Hicks and The King, leading to the decisive race in California. Lightning is then diverted to Radiator Springs before he can compete.
The Los Angeles International Speedway is fictional, like many locations in the Cars universe. The race establishes Lightning's ambition and his fixation on winning the Piston Cup, which the rest of the story gradually challenges.