In Pixar's Cars 2, Mater is mistakenly recruited to be a spy.
Mater becomes involved in espionage after Finn McMissile and Holley Shiftwell misinterpret his accidental actions as evidence of secret-agent skill. He is actually Lightning McQueen's loyal tow truck friend, but his unusual behavior and unfiltered comments make the spies believe he is an undercover operative.
This misunderstanding drives the comedy of Cars 2. Mater travels through the World Grand Prix while trying to help Lightning and simultaneously receiving instructions from the spies. His apparent foolishness often turns into useful improvisation, allowing him to uncover information that more polished agents miss.
The spy plot also introduces Finn McMissile, Holley Shiftwell, and Professor Zündapp. Their investigation concerns sabotage connected to Allinol, the alternative fuel promoted during the international race. Mater's mistaken identity gives the sequel a different structure from the first film, which focused mainly on Lightning's personal growth in Radiator Springs.