It's been a few years since Lightning McQueen, the small-town hotshot, became a world champion. Life in Radiator Springs has been quiet, with Mater, his best friend, enjoying the peace and quiet. However, Mater's life is about to take a drastic turn.

As Mater joins the espionage team, he's introduced to the villainous world of Professor Zündapp, a disgruntled scientist turned mad by his past failures. Zündapp, with the help of his loyal accomplice, a menacing car named Vladimir, plans to disrupt the world's oil supply using a mind-controlling electromagnetic pulse device.

During their mission, the team encounters a range of zany characters, from sassy Citroen DS to sexy, gadget-laden Italian sports cars. Mater's innocence and comedic timing prove to be the perfect antidotes to the high-stakes espionage, making him an unlikely hero.