Rust-eze is Lightning McQueen’s sponsor at the beginning of Pixar’s Cars.
Rust-eze is a fictional brand of medicated bumper ointment, and its sponsorship places McQueen in the company of a smaller, less prestigious racing team when the story begins. McQueen initially wants to leave Rust-eze and secure the more famous Dinoco sponsorship.
The sponsorship becomes part of McQueen’s character arc. His early obsession with status and a better sponsor gives way to greater respect for the people who supported him before he became a celebrated racer.
Dinoco is a different fictional racing sponsor associated with the Piston Cup and Doc Hudson’s history. Octane Gain and Mood Springs are also fictional brands seen in the racing world, but neither is McQueen’s initial sponsor.