Access all G2 Circuit Cars:
In Championship Mode, after entering your name and hearing from the racing
teams, you come to the GT2 Circuit menu. It says, "Teams/Even Select",
"Save Game", and "Main Menu" on the left. Using the SECOND Controller,
press Z, Right, Z, Z, Z, B, Down-C, A, Right, START. There will be no
notificatoin and the screen will advance when you hit A, but all of the
GT2 cars will be available. Note: No experience points will be gained and the
same number of Gold Cups will still be needed to unlock events.