Professor Zundapp: Lightning McQueen cannot win the race.
Grem: Instead of saying "ka-chow, " he's gonna go "ka-boom!"
In the scene where Mater enters the terminal at the airport, a mark showing that his symbol was completely scraped off is visible on one of his sides, but when he goes through the gate, that mark is no longer there.
During the last race in London, Lightening passes by a sign that is advertising Lassetyre. That is a shout out to John Lasseter one of the directors of the movie.