Get additional cash, nitrous energy or speed boosts by driving through carefully placed icons around the track.
Invincible Mode
When you go to Los Angeles, on the second shortcut, when you use full nitro speed, smash into the wall just after the curve. It might take a few tries. When you see that you suddenly popped to the normal track, you will see that you're screen is still blue, the way it is when you use full nitro. The only thing is that you are still traveling at normal speed. You now can hit any car without slowing down. The only way to get out of this mode is to do drift, a knockdown, or get wrecked. There is only one bad thing. You can't use nitro anymore. It is still a great cheat to try.
Upgrades
It's always worth spending some money and putting something extra under your hood. There are 6 upgrades to choose from, these are: Top Speed, Acceleration, Nitrous, Nitro Efficiency, Handling and Armor.