To go to Level 3 with the DMG 1000, $20000 in your pocket, and a range of weapons, press ABRACADABRA on the title screen (where R is Right and D is Down). If put in correctly then a police siren will go off.
Enter the below codes at the "Game Options" screen:
To start with a fully upgraded Bike and $1,000 in extra cash, at the title screen, on Control Pad 2, press Up, Down, Down, Right.
At the title screen on controller 2 press B, Left, Up, Right, then press Start. You will start with $3330, on level 3, and you'll get Wild Thing 2000 (fastest bike in the game).
Enter the following passwords at the password screen...