I had a regular car tire on a rim in my trunk and hit a tree head on. When I retained consciousness the tire was on my passenger side seat.. Sort of. I climbed out and ran away as there was smoke. The tire broke the headrest and the seat and cracked the dashboard and wedged itself between the floor and seat. Its a bit blurry but I remember clearly seeing how close to death I was and the friend I just dropped off having been even closer.

Stuff in hour trunk can kill you.