How did 'vettes get this reputation. I had a friend that owned a 'vette and was driving it in sub zero temps on the highway. The guy in front of him must have had trouble starting his car that morning because his hood wasn't latched well. The hood flew open and was ripped right off. The hood hit the 'vette, corner first, nearly dead center in the door. This knocked off the paint and made a small gouge in the gelcoat about the size of a quarter. Try that with a metal body.
When I built my dune buggy, I was a regular reader of Kitcar magazine. They did an article on repairing fiberglass. They chose to cause some damage to a front fender of a Saxton (Austin Healey replicar). First a large ball peen hammer was taken to the front fender. After several whacks caused no damage, they got out the big sledge hammer. Several more whacks and still no damage. Finally they bit into the fender with a 24" pipe wrench and managed to tear off a couple of chunks using leverage. Again try that with a metal body.
Ok, so on the con side, there are some surface cracks in the gelcoat on the very front of the hardtop for my '55 Thunderbird. Of coarse the top is 45 years old and resins have come a long way since 1955.
The truth is that a quality fiberglass body (I picked AJs) will stand a lot more punishment than a metal body ever could. If you should manage to cause some damage, fiberglass is much easier to repair, just save any large pieces.
