In Pixar's Cars, Lightning McQueen wins the Piston Cup at the film's end.
The film's climax is a three-way final race between McQueen, Chick Hicks, and The King. McQueen is positioned to win, but he stops before the finish to help The King after Chick Hicks deliberately crashes him. Chick crosses first, yet the crowd rejects his unsportsmanlike victory, and McQueen refuses to accept the Dinoco sponsorship that would have followed a conventional win.
Because McQueen helps another racer finish, the Rust-eze team keeps him as its driver and Dinoco chooses a different arrangement. The Piston Cup is the fictional championship trophy at the center of the original film's racing story.
The Florida 500 belongs to Cars 3, while the World Grand Prix is the international series in Cars 2. “Dinoco 400” is not the championship race name used in this finale.