I've heard Big Rigs Over the Road Racing has some pretty good soft body physics.
I know that the Rigs of rods developer are making a game called beamng, it will use Soft Body engine.http://www.youtube.com/watch?list=UUPLAYER_beamng&feature=player_embedded&v=9JPDtDfxf6w
Burnout Paradise is fun to get a really fast car, slam it into a wall, and watch the crash.