Cheat codes:

Faster Driving Tip:
Press The right analog stick up to crouch down and go faster.

How to Increase Karma Meter:
This keeps opponents from hitting you back. To increase it always use X after hitting a racer on your team to apologize.

How to Increase Speed Meter:
Drive at top speed and make comebacks to increase the speed meter which controls the speed of your kart.

Increase Stunt Meter:
Do stunts to increase the fun meter which will in turn allow even more stunts.

More Points:
After you land on 2 wheels add a spin or a flip for more points.