Which Pixar Cars character was voiced by racing driver Mario Andretti?

Mario Andretti voices a character based on himself in Pixar's Cars 2.

Andretti appears as a cameo character in Cars 2, where he is presented as a famous racing car attending the World Grand Prix events. The appearance connects Pixar's fictional racing world with a real motorsport legend. Andretti is one of the most internationally recognized American racing drivers, having competed successfully in open-wheel, stock-car, and sports-car events.

He won the 1969 Indianapolis 500 and the 1978 Formula One World Championship. Those achievements made him an especially fitting guest for a film built around a global racing competition. Pixar also included other real-world racing personalities in the Cars franchise, including Michael Schumacher and Jeff Gordon.

The question refers to the voice cameo, not a fictional racer whose design resembles a real driver. Mario Andretti's Cars 2 appearance is brief, while the principal speaking roles belong to characters such as Lightning McQueen, Mater, Finn McMissile, and Holley Shiftwell.