Enter "ALL." as a code at the cheats screen to unlock all bonuses.
Enter "PINT" as a code at the cheats screen to unlock all cars in arcade mode.
All Prototype parts:
Get 1,500 respect points from every CPU character.
Successfully complete all the series in Arcade mode, except the Extreme Nitrous Series, to unlock the Bronze, Silver, and Gold Prototype Challenge Series.
Enter "CASH" as a code at the cheats screen.
Enter the code FAST at the code section to get Unlimited Cash.
Win All Races:
Enter "WIN." as a code at the cheats screen.
For best results, get a Corvette Z06 and go to the test track. Start driving backwards. Go to the curb with the crane sticking over the track, then drive into the dirt. You should see hardened dirt. Drive onto that until you get halfway through the hardened dirt, then drive off slowly as if you are going back onto the track. Before you get back on the track your car should start to bounce and shake. When you come out of it, your car should be badly damaged.
Character Test Mode:
Enter "CHAR" as a code at the cheats screen.
Get a 100% completion in career mode to unlock prototype mods for all cars in career mode and the Extreme Nitrous Series in Arcade mode.
Drag Race Exploit:
Also, when you have enough money ($10,000 is a good amount to start with) you can host your own events. Make it a sprint and allow only class 1 cars. You will get 2 racers (T.K. ans Biggi) and they will have either a corvette or a viper (99% of the time) always choose the viper as it is much faster than the corvette. If both drivers have the same car look for which car has the higher BHP. If they are identical, choose Biggi as he is the better driver and will win most of the time.
In career mode, go to your garage and do something with one of your cars (for example, switch a part or get a different paint job). The game should autosave. Then, go back to your race menu. Go in a sprint and bet all your money on one car that looks the fastest. It it does not win at least three races out of four, turn off the PlayStation 2 and turn it back on. It will load your last autosave. Try the same sprint again until you win then find a different sprint and start the entire process again.
Everyone Respects You:
Enter "RESP" as a code at the cheats screen.
Free metallic paint:
Go to the paint menu in career mode in the workshop. Highlight "Metallic" and press X. Once in the color selection screen, press Triangle. Go to the base color and chose one. The original base color will now be active as a metallic color. For example, if the original base coat is red, if you highlight black as the base color the car will appear as black with a red metallic coat. This does not work if the car has been repainted already.
Enter "CREW" as a code at the cheats screen.
Pink slip races without losing your car:
Enter any type of pink slip race (for example, the sprints). Once you select the pink slip race, remove your memory card. Select "OK" for the race, the no memory card found message, and disabling auto-save. If you lose the race, exit back to the title screen, insert your memory card, and it will load your career with everything you had before the race (car and respect points)/ If you won, exit to the career screen and select "Extras" to enable auto-save. Keep doing this to get a lot of cars or sell them to get money quicker.
PS2 Memory Card Exploit:
When you have 600 respect points from any crew leader, you can challenge them for their car. These races can be difficult as a defeat will result in you losing your car. If you remove you memory card before challenging the leaders, you can prevent this from happening. If you lose the race, simply reset your PS2 and load your game from your card. However, if you win the race, re-insert your memory card and use the autosave function in the Extras menu to save your data.