Hidden Characters
Sent in by Jan Wargalla

At the mode select screen, hilight the practice mode and press 
Start, Up, Right, Down, Right, Start. You will hear a sound to 
confirm that it worked and you will see "Here comes a new
challenger" on the bottom of the screen. This trick reveals
all of the hidden charcters.
Note: This trick may not work in the American version.

For Extra Cars 
Sent in by Justin Beeler

Drag race with the jaguar and when the drag race is over, 
quit and wait for it to ask you to enter your name. Enter 
your name as SAUSAGE. You might want to save it on
your memory card or you will have to keep entering it in 
each time you play the game. 

Reversed Tracks 
Sent in by Justin Beeler

To get the reversed tracks you need to drag race again with 
the jaguar, well on these codes it don't matter which car but 
the jaguar is the fastest, when it is over, quit. When it 
asks you to enter your name, enter it as KNACKED, and again 
you might want to save the game on your memory card. 

Get a nitro boost for each time you honk your horn 
Sent in by Justin Beeler

Enter your name as WHOOOOSH

To get small cars 
Sent in by Justin Beeler

Enter your name as MJCIM.RC

Sent in by Sean "puppy" Staeger