Enter "MATTL66" as a code to unlock all races.
Enter "IF900HP" as a code to unlock all tracks and mini-games.
If you get lost in the desert, follow Mater or any other car without bumping into them and they will take you back to Radiator Springs.
Enter "WATCHIT" as a code to unlock all movies.
Enter "R4MONE" as a code to unlock all paint jobs.
Enter a race in Arcade mode. When you get to the finish line on the last lap, jump at the last moment. You will keep jumping until your character stops talking.
Enter "VROOOOM" as a code.
Enter "IMSPEED" as a code.
Enter "TRGTEXC" as a code.
Enter "YAYCARS" as a code to unlock all cars.
Enter "CONC3PT" as a code to unlock all concept art.