In Pixar's Cars, the retired racer who secretly trains Lightning McQueen is Doc Hudson.
Doc initially appears to be Radiator Springs' local judge and doctor, but Lightning discovers that he was once the Fabulous Hudson Hornet. Doc won three Piston Cups before a serious crash ended his racing career and left him bitter about the sport's treatment of older champions.
After Lightning is ordered to repair the town's road, Doc reluctantly begins teaching him how to turn and control a car on dirt. These lessons are not simply about speed. Doc wants Lightning to understand patience, balance, and the value of skills that cannot be measured by a race result.
Doc's history explains his dislike of publicity and his guarded attitude toward Lightning. He eventually supports the young racer, but his own racing career remains in the past. Paul Newman voices Doc, whose character is inspired partly by the real Hudson Hornets of early stock-car racing.