I've been in many accidents while not wearing a seatbelt. The worse was when I killed my old 1972 Chevy Luv. We did a flip with a full twist. It was bashed in the front left and right rear, and there was a nice 45 degree crease down the passenger side. (Imagine taking a piece of paper and folding down one corner.) It also ended up facing in the direction we were coming from, on top of the rear window. My cousin and I walked away with nothing more than some bumps and bruises.