Sir Miles Axelrod was behind the whole thing. He invented Allinol and the microwave camera to make cars break down thus forcing them back to fossil fuels and making him rich. Mater is knighted by the Queen of England as a reward for exposing Axelrod. He returns to Radiator Springs where he is recognized as a hero. Finn and Holly stop by and Holly introduces herself as Mater's girlfriend.
Continuity mistake: Tony Trihull appears when Finn McMissile begins chasing Professor Z. It also shows when Tony uses his magnet. When it is used, Finn's equipment are pulled by the magnet, which includes his bullets. Those bullets are black when all of them were going out. However, when they are pulled onto the magnet they are grey.
Trivia: The Pizza Planet truck is visible cheering on the right side of the track at the World Grand Prix in Radiator Springs at the end of the movie.(01:37:45)
Answer: They heard him recording the message to Finn and found his words suspicious.