Professor Zundapp: Lightning McQueen cannot win the race.
Grem: Instead of saying "ka-chow, " he's gonna go "ka-boom!"
Mater sees a weary car at the beginning that has leaked oil and tows it. As Mater tows away the car, the car's tyre goes right through the oil leak. Yet no trail of oil is made, even though the tyre goes right through it.
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.