Successfully complete the game to unlock Armageddon mode. In this mode, everything that is destroyed explodes.
Go to any Target with a DS Download Station, and download the Transformers DS trailer to unlock Skydive.
Successfully complete the game. When you choose Overworld at the title screen, a character selection screen will appear.
Collect 250 WiFi Tokens to unlock the Long Horn.
Collect 500 WiFi Tokens to unlock the Psycho Cars cheat. This cheat makes cars constantly hit you in Free Roam mode.
Collect 750 WiFi Tokens to unlock the Gunner.
Collect 1,000 WiFi Tokens to unlock the Infinite Energy cheat. Alternately, get a 100% completion.
While playing in Free Play mode, press Start. Then, go to "Vehicle Form" and select "Confirm". Press B to return to the game with full health and no wanted level.
Go to the Tranquillity Museum with Create-A-Bot using the Hot Rodder form. Find the fountain and drive up to it slowly, facing east. When the front of the car is touching the fountain, stop, then press B + R. The car will boost off of the fountain and fly high into the air. This requires practice, and will not work every time.
Go to the Tranquillity Museum with Create-A-Bot using any ground vehicle form. Find the building with two large smokestacks, located near the bridge between Downtown and the Junkyard. Climb up one of the smokestacks, then change to Vehicle mode. If you are on the northern smokestack, face north. If you are on the southern smokestack, face south. Hold R to boost off of the smokestack. Continue holding R, and Create-A-Bot will float in one place until his boost energy runs out.