http://pages.prodigy.net/jforgione/MB_S500.html

Put the mail on hold, leave out a big bag of cat food, bolt the door and don't come out until you're done reading JimF's website

There's no description of what's normal per se, but it's typical to creep over 100C in traffic with the AC on. You should see a steady 85C or some sane number like that when you're cruising.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD