Select "Options" at the main menu, then "Cheat". Enter one of the following passwords to activate the corresponding cheat function.

All Arcade mode events
Enter SLVRKEY as a password.

All Lightning McQueen custom kit parts
Enter GR8MODS as a password.

All Lightning McQueen friends
Enter EVRYBDY as a password.

All paint jobs for all non-Lightning McQueen characters
Enter CARSHOW as a password.

All Story mode events
Enter GOLDKEY as a password.