In Pixar's Cars (2006), Lightning McQueen's primary sponsor is Rust-eze.
Rust-eze is the fictional automotive product company that sponsors McQueen when he enters the Piston Cup season. Its branding is visible on his red race car, and the company is associated with a rust-removing product. McQueen initially dislikes the sponsor's image because he wants the prestigious Dinoco sponsorship, but Rust-eze remains central to his racing career.
The sponsor is also important to the film's story because Rust-eze founders Rusty and Dusty Rust-eze bring McQueen to Radiator Springs. Their support helps connect the rookie racer to the town and to the lessons he learns there. A common mix-up is answering “Dinoco”: Dinoco is the coveted sponsor McQueen hopes to win, not his starting sponsor. Rust-eze later remains part of McQueen's professional identity in the Cars franchise.