Almost Infinite height!
You will need two players. Blow up two vehicles, preferably the same weight. Each player will get on a different vehicle, then PK each other. Lift each other until it doesn't let you any higher, then jet pack. You can get onto the bridge in Dublin using this, and the tower in Bay City. Have fun!
More tricks, tips and cheats for this game are right here - Destroy All Humans! 2 cheats
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