Sorry about your troubles, but at least it was resolved quickly and you did it on the track where it would have been safer than on the road.
As for caliper rebuilds, when should we do it. I just bought used e39 M5 front brakes for my 540. Before I install them, should I have them rebuilt?
I cleaned them up yesterday and checked the rubber around the ring and it looked intact and no brake fluid leaking, but since they are sitting in my garage, this potentially could be a good time to rebuild them. So, what should I look for?