Punisher bike
Press 2, 1, 7, 9, 4 at the title screen. The Punisher may now be chosen on the bike selection screen.
Turbo
Press 1, 9, 6, 7, 2 at the title screen. A sound will confirm correct code entry. Select an automatic transmission and begin game play. Accelerate until your bike's speed is 175 mph. Hold C (with the default controller setting) to get a turbo boost to 343 mph. Note: Speed records will be disqualified when this code is enabled.