I started thinking about this when I was at the Optima Challenge race at SEMA. Although they were racing 'street' cars, I noticed (nearly) all drivers wearing fire suits. Then I just saw a link on another site to this thread.
http://forums.nasaaz.com/showthread.php?t=4774
This guy seems to have been wearing most of his equipment, except his head sock if I read it right. And had a proper helmet, not a motorcycle helmet, which is not fire rated. He engaged the fire suppression system. It seems to have taken him 8 seconds to from 1st sign of flames at >100mph to out of the car, and he still had IMO significant injuries.
Now I know we have a lot of fast cars here. How many of you with fast cars, let's say 12.50 and less, or you fast auto-x/time attack/road course guys wear a fire suit or other safety clothing other than the required helmet? How about fire suppression?