Unlock All Drift Tracks
Press Left, Left, Left, Left, Right, R2, R1, L2 at the main menu to unlock all drift tracks.
50% success rate. 

Infinite Nos
Press X, X, Triangle, Triangle, X, X, O.
Submitted by benflame. 33% success rate. 

Unlimited Turbo
Press X, O, Triangle, Triangle, X, X, O at the main menu for unlimited turbo.
9% success rate. 

Unlock All Sprint Tracks
Press Up, R2, R2, R2, R1, Down, Down, Down, Down at the main menu to unlock all sprint tracks.
0% success rate. 

Unlock All Circuit Tracks
Press Down, R1, R1, R1, R2, R2, R2, Square at the main menu to unlock all circuit tracks.
0% success rate. 

Unlock All Drag Tracks
Press Right, Square, Left, R1, Square, L1, L2, R2 at the main menu to unlock all drag tracks.

Flip Opponents Car
To flip your opponents car get right behind him so that your bumper is touching the back of his car and then hit the nos button and then that should make him flip.
Submitted by benflame. 

Unlock Samantha's Car
Get 2,000,000 style points and the raise the bar up 1 more time.
Submitted by benflame. 

Get Junkmans Ride
First get Samantha's ride and then raise the bar 1 more time and it will say you recieved Junkman's Honda Civic.
Submitted by benflame. 0% success rate. 

Go to: Need for Speed: Underground Info Page | nGaming Home Page.