Example...my friend's Fiero was hit in the back at 10mph. Sure...just needed a new bumper...right? Nope, it knocked out the oil pump and seized the engine. What's the likely hood of something like this happening to a Z...who knows? But things can get shifted and off causing problems. Maybe the radiator was screwed up and overheated. One thing is for sure. It's sketchy to have a NA motor in a TT chassis and see 1/4 panels replaced.