5-0 Mode:

Enter "BDK" as a code at the cheat menu.

Sidecar Mode:

Enter "CMB" as a code at the cheat menu.

Jailbreak Mode:

Enter "KLFSDA" as a code at the cheat menu.

Four Nitros in Jailbreak Mode:

Enter "FDMFG" as a code at the cheat menu.

Hitch A Ride:

Position your bike behind a car and pop a wheelie. Just as you begin to jump, slam on the brake. Now you're car-surfing. Do this when a cop is chasing you. However, when he rams the car, both of you will wipe out.

No Arrests or Crashes:

Press Start and then restart the race before getting arrested by the police or crashing.

Keep Weapons and Don't Loose:

If you have lost your weapon and you're near last place and right by the finish line, just pause the game and go to restart, then yes. When you restart, you will have another chance at 1st place and you will also still have your weapon.

The Slacker's Method:

If you are really lazy and want to win races easily just do this. After the 3-2-1 just turn around and drive in the wrong direction for a bit. KO any cops or stuff and do not get busted or wrecked. Then all you have to do is, after a while of driving the wrong way, just press START then QUIT then YES. It should say you came first. This works on random tracks so sometimes you might get wrecked. This works in Sidecar Co-op and possibly Solo mode