I would just like to send up a red flare based on my experience...I have a 1996 S420 with an electronic transmission..."Sealed for life". The car was serviced at MB dealerships throughout its entire life. I have every record. But the transmission was shot at 87,000 miles for no reason at all according to MB. The dealership replaced the tranny with a factory rebuild...the cost was @ $6,000. The moral of the story is replace that fluid...don't let it go past 60,000 miles, and you shouldn't have any problems.
Personally, I would question any MB with a similar transmission over 80k...no fluid change, no sale.