The Florida 500 is the race at which Lightning McQueen trains Cruz Ramirez in Pixar's Cars 3.
The event is the film's climactic stock-car race. After McQueen suffers setbacks against the younger Jackson Storm, he and Cruz switch from a conventional teacher-trainee relationship into a partnership that combines his racing knowledge with her developing confidence and ability.
The Florida 500 takes place at the fictional Florida International Super Speedway. McQueen initially intends to use Cruz as a trainer, but the story increasingly reveals her own potential as a racer. The race therefore resolves both McQueen's competitive crisis and Cruz's uncertainty about her future.
The Piston Cup is the championship associated with the Cars series, while the World Grand Prix is the international event in Cars 2. Neither is the name of Cars 3's decisive race.