The retired race car voiced by Paul Newman in Pixar's Cars is Doc Hudson.
Doc is the judge and medical doctor of Radiator Springs, and he initially distrusts Lightning McQueen's reckless attitude. His hidden past is revealed when Lightning learns that Doc was once the famous Hudson Hornet, a three-time winner of the Piston Cup.
Paul Newman, a celebrated actor and former racing enthusiast, provided Doc's voice. Cars was his final major acting performance before his death in 2008. Newman had real connections to motorsport through professional racing and ownership of the Newman/Haas Racing team, making his casting especially fitting.
Doc's story connects the film's fictional world to the history of American stock-car racing. The real Hudson Hornet was a successful automobile produced by the Hudson Motor Car Company, and its racing reputation inspired the character's name and backstory.