Need for Speed: Underground Cheats

easy drift points:
Simply stay behind a car and watch the points rack up.
Unlock all sprint tracks:
Go to the main menu then hit up, X, X, X, R, down, down, down.
easier drag wins:
To get to higher gears quicker in drag races, tap L repeatedly to increase the revs to the appropriate level to switch gears.
Unlock all drift tracks:
Press Left(4), Right, X, R, Y at the main menu.
Unlock all circuit tracks:
Go to the main menu then hit down, R, R, R, X, X, X, Z.
Unlock drift Physics on all cars:
Go to the main menu then hit R, up, up, up, down, down, down, L.
Unlock All drag tracks:
Press Right, Z, Left, R, Z, L, Y, X at the main menu.

Use the following customizations to reproduce the Brian's Nissan Skyline from 2Fast2Furious:

in the main screen enter this ----> seemylvl2parts.

To unlock all visual upgrades for single and multiplayer mode, simply complete Underground mode.

Unlock the Mystikal car by doing 10 laps on drift track 1 and play
through underground mode to get drift track 6.For maximum prizes get the
Mystikal car and go to drift track 6 and set it on 10 laps. I have
gotten 330,115 style points and unlocked 9 prizes literally!

Look for alternate routes on your in-game map while driving. These can get you ahead of an opponent easily or shave off seconds on your timer. They will look like another road on the map, but sometimes are narrower. Most of the time these shortcuts will be hard to see or take, and can be extremely risky.