If you are so sure they are not safe, then why build one??? A cage is a good idea in any hot rod that is used on the street. Heck, motorcycles aren't safe, go carts aren't safe, heck if you believe everything you here breathing isn't safe.

Absolutely, you flop a glass car and it's gonna put you in a bad hurt.....We all realize the risk. And we accept it. If you want a collapsible column, full cage, side impact door beams, a perimeter frame, crumple zones, and all the other safety things that are in grandmas car then it would appear you have two choices, !. Build them into your car, 2. go buy a Volvo. Just don't try to convince me that I need all that BS on my car, if I crash and it kills me, big deal. Life's just that way, nobody's lived through it yet!!!