To those of you not worried about sun affecting your phone, the friction mount from Arkon works great. It doesn't move around at all, even on the highway! I haven't had an overheating issue yet, but if I do, I'm going to give it to my mother for her GPS and order the one Jason has.
the sun shinning in was always a problem for my Droid when i had it in the windshield. otherwise i would have gotten the same Arkon cradle but with the windshield mount. it may vary from car to car based on the shape, size, and slope of the windshield, but in my car it was always a problem, and i did not want to subject my Incredible to that kind of abuse.