The filmmakers knew no one would watch Cars with a keener eye than professional racing fans. Stock car legend Richard Petty was brought in to provide authenticity, then stayed around to provide voiceover for the 1970 Plymouth Superbird that shared his nickname “The King.” Pixar teams also took extended field trips to some of America’s biggest speedways, looking to capture the sensory overload of rumbling engines, blinding floodlights, and the smell of exhaust, burning rubber, and tailgate barbecue.