Enter PING as a code at the cheats screen to unlock all cars in arcade mode. If that hasn't worked then try putting in PINT instead and hopefully that will unlock all the cars in arcade mode.

You must enter FAST.

You must acquire 1,500 respect points from all CPU characters.

This only works with 4WD/AWD cars equipped with nitrous oxide. Enter a drag race with such a vehicle and before the race starts, shift your car into 5th gear.

At the moment the race starts, use nitrous and you will quickly reach you top speed and beat out your opponents before the finish line. I have never lost when doing this properly, so I also bet with drivers to get the maximum money possible.

Submitted by scottwilson802

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.

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.