Access Bike Cheat:

On the Chararcter Select Screen, quickly Press L, R, L, R, L, R *OR* L+R, L+R, L+R. Then highlight the driver you want, and Hold L+R and Press A.

MPH, In Car View, & Cinematic View Cheat:

Start a game and during the game (do not pause) put a controller in Controller Port C or if you have only one controller you can take that out and move it to Port C, then Press Start on that controller now if you:

Press X five times you will get your MPH.
Press B and youll get an Inside The Car View.
Press Y you will get a Cinematic View!
Press A to go back to your normal view.

Another Day Mode Cheat:

On the Character Select Screen Press R, now Hold R while selecting your driver. If done correctly, it should say Another Day.

Turn Off Arrow Indicators Cheat:

Just before the Character Select Screen appears, Hold R + Start. If done correctly NO ARROWS should appear.

Turn Off Destination Mark Cheat:

Just before the Character Select Screen appears, Hold L + Start. If done correctly NO DESTINATION MARK should appear.

Access Expert Mode Cheat:

Just before the Character Select Screen appears, Hold L + R + Start. If done correctly the word EXPERT should appear.