Finn McMissile, a British spy, infiltrates an oil rig owned by a group of lemon cars to rescue a fellow spy. He witnesses the lemons, seemingly led by Professor Z�ndapp, load an electromagnetic pulse emitter, disguised as a camera onto a shipping crate. After finding out the agent he came to rescue is dead, he flees and fakes his death.
Lightning McQueen is now a four-time Piston Cup champion after the recent death of his mentor Doc Hudson, and returns to Radiator Springs. However, Italian formula race car, Francesco Bernoulli, challenges McQueen to race in the newly created World Grand Prix, led by its creator Sir Miles Axlerod, who intends to promote his new environmentally friendly fuel, Allinol. McQueen and his best friend Mater � along with Luigi, Guido, Fillmore, and Sarge � depart for Tokyo for the first race of the Grand Prix.
At a World Grand Prix promotional event, Mater makes a scene after leaking oil and eating a bowl of Wasabi, angering McQueen. While cleaning up, Mater interrupts a fight between American spy Rod "Torque" Redline (whom McMissile and his new partner Holley Shiftwell attempt to meet) and lemons Grem and Acer. Redline passes his information to Mater, whom Holley mistakes as a spy. Meanwhile, Redline is captured and killed by Professor Z�ndapp, who reveals that Allinol combusts when hit with an EMP pulse. Z�ndapp informs his superior, an unknown mastermind, that Redline passed on his information.
At the first race, three cars are ignited by the camera. McQueen places second in the race after Bernoulli, due to Mater accidentally giving him bad racing advice while evading Z�ndapp's henchmen with help from Holley and Finn. McQueen snaps at Mater, who is abducted by Finn while attempting to return to Radiator Springs. After traveling to Paris to collect more information from Finn's old friend Tomber, they travel to Porto Corsa, Italy, where the next race is being held. During the race, Mater infiltrates the criminals' meeting, just as the camera is used on a few more cars, causing a multi-car pileup, while McQueen finishes first. Due to increased fears over Allinol's safety, Axlerod lifts the requirement to use it for the final race. However, when McQueen decides to continue using it, the criminals plot to kill McQueen in the next race in London. This spooks Mater, causing him to blow his cover and allow him, Finn, and Holley to be captured.
