Four-time Piston Cup champion race car Lightning McQueen (Owen Wilson) returns home to Radiator Springs and reunites with best friend Mater (Larry the Cable Guy) and girlfriend Sally Carrera (Bonnie Hunt). Former oil tycoon Miles Axlerod (Eddie Izzard), now a green power advocate, announces a racing series called the "World Grand Prix", as a means to promote Allinol biofuel. Although McQueen initially refuses to participate, Italian formula race car Francesco Bernoulli's (John Turturro) challenge, as well as Mater's intervention, leads McQueen to enter the Grand Prix. At Sally's urging, McQueen agrees to take Mater with him, only to have the tow truck embarrass him repeatedly in Japan with his jovially ignorant antics.
Meanwhile, a group of "lemon" cars led by Professor Zündapp (Thomas Kretschmann) and an unknown mastermind owns the largest untapped oil reserves in the world. They secretly plot to secure their oil profits by using a weapon disguised as a television camera to ignite the Allinol fuel in targeted race cars during the World Grand Prix; with no apparent cause for the explosions, the public would doubt the fuel's safety and depend further on the group's oil. British spies Finn McMissile (Michael Caine) and Holley Shiftwell (Emily Mortimer) attempt to foil their plot. They attempt to rendezvous with American spy car Rod "Torque" Redline (Bruce Campbell) at a World Grand Prix promotional event in Tokyo in order to receive information about the mastermind; however, Redline is cornered by Zündapp's henchmen and passes his information to an unsuspecting Mater before being captured and subsequently killed. As a result, Shiftwell and McMissile mistake Mater as their American contact.
