Also, no obstructions (leaves etc.) around the AC. The dealership that did the service work on the car before I got it DID do extensive work to the AC system.

This problem started a couple of weeks ago after I had the car on the Interstate on a hot day (about 30 minutes). It ran around 90 and then went up to 115. NOW, the car will "pin" to around 110 after driving for 10 minutes @60 mph.

Now, I'm kind of a gauge freak, but no other Mercedes that I've owned has ever run this hot. Normal?? You tell me.