After the events of "Cars 2," British spies Finn McMissile and Holly Shiftwell embark on more missions throughout the world. The conflict between lemon cars and non-lemon cars is still going on and Professor Zündapp (Z) is plotting revenge. Mater, who was knighted for exposing Axelrod's scandal gets called in every now and then and he and Holly grow closer. There could also be flashbacks showing how Finn and Holly became agents. They will also find out about the misunderstanding of Mater being the American agent, when really it was the late Rod Redline, who passed the device to Mater while he was injured.
