IMO and experience the braking requirements for road courses and autocross are quite different. On a road course the speeds are much higher and the time on track is much longer. The SN197 Mustang is a fairly heavy car and brake fade is a real concern. Track capable pads, high temp fluid and air cooling ducts will be necessary especially as skill levels increase. In autocross the speeds are lower and the time on track is much shorter. If you're on track for much over a minute in an autocross the course is either unusually long or you're just slow. The main braking requirement in autocross is good initial bite and modulation. The last thing you want in autocross are pads that need to build up a lot of heat before they work well. The only thing in autocross that taxes the brake's fade resistance is the fact that the corners come at you much more quickly than they do on a road course. During an autocross usually your left foot is either braking or hovering just above the pedal while your right foot is operating the throttle. On a road course even in a fast car with a skilled driver there is a little time between corners for the brakes to cool a bit. This is where air cooling ducts really come into play. The only time I got the brakes fairly hot at an autocross was several years ago in my '72 'Cuda at a fun autocross where we could make as many back to back runs as we wanted. It was a fast course and I was giving rides to some friends. At the end of the third run I could smell the brakes coming across the exit timers. It still stopped OK, but I didn't think a fourth run would be a good idea either.