No gravity:
Pause game play, then press X, Z, X, Z, Up(3). A sound will confirm correct code entry. Repeat this code to disable its effect. Vehicles in traffic will float when hit.

Low gravity:
Pause game play, then press Z, R, Z, R, Right(3). A sound will confirm correct code entry. Repeat this code to disable its effect.

Unlimited countermeasures:
Pause game play and press Y(3), X(2), Z(2). A sound will confirm correct code entry. Repeat this code to disable its effect.

Transparent car:
Pause game play, then press Left, Right, Left, Right, Z(2), R. A sound will confirm correct code entry. Repeat this code to disable its effect.

Map:
Lightly press L during game play and a faint map will appear.

ATV Boost:
Successfully complete Smuggler's Mission 14.

ATV Monster:
Successfully complete Smuggler's Mission 10.

Baja Truck Bombs:
Successfully complete Smuggler's Mission 7.

Baja Truck:
Successfully complete Smuggler's Mission 4.

D-5 Hondo:
Successfully complete Smuggler's Mission 11.

Du Monde Oil Slick:
Successfully complete Smuggler's Mission 5.

Dual Career Countermeasures:
Successfully complete Smuggler's Mission 36.

Grenadier Bombs:
Successfully complete Smuggler's Mission 25.

Grenadier:
Successfully complete Smuggler's Mission 24.

Hondo Oil Slick:
Successfully complete Smuggler's Mission 15.

Hoverbike:
Achieve a "Great" rank on all Smuggler's missions.

Kavostov Halftrack:
Successfully complete Smuggler's Mission 27.

Kavostov Smoke Screen:
Successfully complete Smuggler's Mission 29.

North America:
In joyride mode, get the token in Russia (on the roof of HQ), then the token in Vietnam (use the V-Boost move to get to the volcano), and the token in Russian Winter (on a small "house" near where you start).

Russian Winter:
Successfully complete Smuggler's Mission 22.

Sahara Smoke Screen:
Successfully complete Smuggler's Mission 20.

Sahara Special:
Successfully complete Smuggler's Mission 18.

Special Du Monde:
Successfully complete Smuggler's Training 3.

Super Buggy Boost:
Successfully complete Smuggler's Mission 2.

Vietnam:
Successfully complete Smuggler's Mission 9.

Hint: East Europe: Secret Token:
You can find a secret token on top of the arch in the town. It is easiest to get it with the Baja truck using the vertical boost.

Hint: North America: Secret tokens:
You can find a secret token on top of the second waterfall. You have to drive around to the top and jump off the edge.

You can find a secret token on the tall mountain directly across from the first waterfall.

There is a secret token under one of the bridges next to the second waterfall.

Hint: Russia: Secret tokens:
You can find a secret token (a small spinning tile with the Rockstar Games logo on one side and the Angel Software logo on the other) at the corner of the level, on a very small island at the top in joyridin' mode.

You can find a secret token on top of the warehouse, which is in the top of the map towards the middle in joyridin' mode. Use the Baja truck with vertical boost and bombs to reach the roof.

You can find a secret token by the river. There is a little dirt jump leading directly to it. It is easy to do with the Baja truck or the ATV Monster.

Hint: Russian Winter token:
You can find a secret token at the burned village in the far corner in joyridin' mode.

Hint: Vietnam: Secret token:
You can find a secret token at the side of the volcano that you can get stuck at if you drive in. It is on the side in joyridin' mode.