Professor Zundapp: Lightning McQueen cannot win the race.
Grem: Instead of saying "ka-chow, " he's gonna go "ka-boom!"
In the credits, there is a paper revealing that Mater was knighted on Tuesday, July 15th, 2011. However, July 15th, 2011 was on a Friday, not a Tuesday.
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.