I think the 10 second rule is just an arbitrary point. I was there at MRI Sat. and saw the two smash ups, neither wher going 140 mph and where tore up real good. If you're bouncing around on the track in a 10.50 or a 9.50 sec car, I think you'll see the same damage. Even at 80 mph, there can be substantial damage. Personally I want to be safe at that speed, my car will be 10.90 at best, but it will have a cage. Looks don't help when things go bad.