Select the 'Statistics' option at the main menu, then press DELETE to return to the main menu. Then, type one of the following codes to activate the corresponding cheat function.
Simply stay behind a car and watch the points rack up.
Easy style points
After you unlock the oval drift track, go into "Quick Race" and choose that track. Then, race around it using the handbrake to powerslide into the corners. Depending on how good you are, you will unlock rewards every time you fill your meter, which does not take too long.
Shoot smoke from nitrous
To make nitrous shoot out smoke, put your car in neutral, or at the beginning of the race press [Nitrous].