Health Regeneration
[Submitted by: Cheat Masters ]
After any given character reaches level 20, that character will begin to automatically regenerate his health as needed.

Vehicles (and more!)
Unlock the following vehicles (and other cheats) by fulfilling the specified requirement.
Cheat Psycho Cars - Earn 500 WiFi Tokens
Funky Bus - Connect to the All-Spark Wars Server
G1 Starscream - Get the Transformers DS trailer from Target stores
Infinite Health - Earn 1,000 WiFi Tokens
Love Cruiser - Earn 250 WiFi Tokens
Stunt - Earn 750 WiFi Tokens

Health Refilled & No Wanted Level
How to: While playing in Free Play mode, press the start button, go to Vehicle Form, and hit select to confirm your choice. Now press B to go back to the game. Your health will be automatically refilled, and any wanted level you may have will disappear.