Keeping the heater on is good advice, but not really practical in 95 degree weather. Plus, the overheating is a sign that something isn't quite right with the cooling system. Other people report their temp gauge never going above half way, even when idling for an extended period of time, so not all M5's are having this problem. To be honest, I'm not that concerned about it since the temp is fine at speed and I don't drive in rush hour traffic or let my car idle for extended periods. The only reason I am trying to fix it is so I can make it through the emissions test. What I really need is a shop that has a decent fan that can move some air through the radiator while the car is on the dyno.