In Pixar's Cars 2, Mater becomes an accidental spy after being mistaken for an agent.
Mater is Lightning McQueen's rusty tow-truck friend from Radiator Springs. During the World Grand Prix, Mater becomes involved with British agents Finn McMissile and Holley Shiftwell. Because of a misunderstanding, the spies treat him as a useful undercover operative rather than an ordinary tow truck.
His clumsy behavior is central to the comedy, but Mater also contributes genuine problem-solving. He notices details that more sophisticated characters overlook and helps expose the conspiracy involving Allinol and the oil interests behind the attacks. The story gives him a much larger role than he had in the first Cars film.
Cars 2 shifts the franchise toward international espionage, with races in Japan, Italy, and England. Lightning McQueen remains a major character, but Mater is the narrative focus of the spy adventure. The film's portrayal is intentionally comic and does not make Mater a formally trained secret agent; he is an accidental participant whose loyalty proves valuable.