Our C36 ran at about 83-87C most driving conditions, stopped in heavy traffic at 35C ambient (close to 100F I think), the temp would rise to 100C, maybe a touch above with the AC blowing as hard as it could.
Sounds like you're running a touch hot. Could be the electric fan, could be the thermostat. Thermostats are cheap and easy, and it's easy to watch for fan engagement.
1998 C230 "Black Betty"