Access to Everything
Enter the nickname "Dead". When you begin the game, hold the Left Shift button, go to the Ride Purchase Menu, and press X + Y + Z + A + B + C.
All the Money
After performing the Access to Everything Code, go back to the Ride Purchase Menu, and press X + Y + Z + A + B + C. The longer you hold the buttons, the more money you receive. Now at any time during gameplay, press A + B + C to receive more money.
Thanks to Revolution reader Jason Beeman!