Iam interested if anyone has had problems with the new M5 in hot weather, say in Arizona. I live in Kuwait and have had the M5 for 18 months. However, in the summer, when the temperature gets over 40 degrees C and if the oil temp is close to 100, then the car has no acceleration, if you press hard, after 4000 rpm in 3rd and 4th gear. It is the same as when you hit the redline at 8000 rpm, when the engine effectively cuts off.BMW spent all winter vtrtying to come up with a solution and this summer, they recalled all the M5s and installed new oil coolers, but this only partially solved the problem.The acceleration is still very sluggish above 4000 rpm.Has anyone had a similar problem in the US? Nader