[Marty Rinehart Jr]

I personally use a HANS devise in my SS/DA Camaro. No, it's not mandated in the rule book. At first I was concerned about driving the finish line with it on. It is not a problem, I never skimp on safety.
In fact, I also have a parachute and a belly pan on our car, which neither are required as well. But, The first year I had it on, I used it at Maple Grove at the 1300 ' mark as our crank broke and every drop of oil was in the retention devise. It stayed there until the car came to a stop. Then it started flowing over the top and on to the track. I really feel it saved me from a top end crash.