In Pixar’s Cars 2, Mater’s job is a tow truck.
Mater travels with Lightning McQueen to the World Grand Prix, where his informal personality causes him to be mistaken for an American spy. His ordinary occupation makes the misunderstanding humorous: Mater is not introduced as a trained agent, but as the rusty tow truck from Radiator Springs. He becomes involved after encountering British agent Finn McMissile and agent Holley Shiftwell.
Mater’s tow-truck identity was established in the first Cars film, where he helps McQueen and works around Radiator Springs. Cars 2 places that familiar character in a much larger international adventure involving Tokyo, Porto Corso, and London.
Mater’s accidental role as an intelligence operative does not replace his day job. The spy plot is the story’s comic complication, while “tow truck” remains the vehicle type and occupation that define him.