1998 C280 Temperature running higher.

I hope someone can help me with my 98 C280. I have owned it since it was new and I take methodical care of it. However, About a month ago, it started running hotter than it has at any time in the last 3 years. There is no apparent damage to the radiator or cooling lines and all frontal shrouds are in place. The temp has never been above an indicated temp of 80-85C. Now, the Temp is always 85-95C. The electric fans now run in high speed a lot more often than they use to and the front right quarter panel is extremely hot to the touch. I verified with a calibrated temp meter that the temp of the top cooling line at the engine is running between 88-93C at idle with an ambient temp of 75F and AC on. The dealer has replaced the coolant tank cap, flushed the system and changed the thermostat. Oil level is in spec. (Mobile 1 10-30). The dealer states that that temp is in spec for my car and are happy with the way it is running. However, they have no explanation why the outside front right quarter panel is so hot or why the temp is indicating higher and why the cooling fans are running more often. The car has never had any damage or mods done to it. Any suggestions would be appreciated. Should I insist they change the water pump? The car is still under warranty. Thanks!

Brian