To change your game's bonus code simply delete the save file on your XBOX, start the game up and create a new profile.
This is useful for those who have found cheats for different bonus codes.
To Unlock the Honda Series and the championships it encompasses, either complete the World Tour or visit the link to the Honda Website mentioned on the game.
To unlock all cutscenes in the game, enter the code '1XP82YEQ4LQX9'.
To unlock the Honda Championship for the bonus code '5011' enter the code 'NYRDJQJK63RM7'.
To unlock the turbo boost type in the code 'U5TP2RED9R3X3'.
NB: This code will not work in the career mode.