Destruction Derby Arenas Rough Justice and bonus cars 1-3 unlocked
Unlock all tracks and arenas in Champoiship mode. Then, get first place in all arenas in Destruction Derby mode to unlock Rough Justice and bonus cars 1, 2, and 3.
The Dam and bonus cars 4-5 unlocked
Unlock all tracks and arenas in Champoiship mode. Then, get first place on all tracks in Wrecking Race mode to unlock The Dam and bonus cars 4 and 5.