Need for Speed – Underground – Platform: Gamecube

While in the Main Menu Screen, enter code:
All Drag Tracks
Right, Z, Left, R, Z, L, Y, X

All Drift Tracks
Left, Left, Left, Left, Right, X, R, Y

All Sprint Tracks
Up, X, X, X, R, Down, Down, Down,

All Circuit Tracks
Down, R, R, R, X, X, X, Z

Have both the Katana and Dual GT Spoiler:
Play through the game normally, and once you beat
Samantha’s Big Tease (#77), pick the Katana Unique
Spoiler. Now, to get the Dual GT, trade in your car
for a Peugot 206. Then, trade your car back to what
you had and now your car has Dual GT as the spoiler.
To switch back for the Katana Spoiler, just go to
spoilers and scroll all the way to the end, and
there’s the Katana spoiler! Once you do this, you now
will have both Katana and Dual GT in the customize ride
from the main menu.