Synthetic fluid is GREAT but there isn't any way that it will last the LIFE that the transmission can last!! The fluid should be changed before the car gets out of warranty!!
All 1996 & later V-8s & V-12's have the .6 trans. ALL 1997 & later cars also have the .6 transmission.
I have posted warnings on these transmissions many times on this board!! Change the fluid!!
I would think that you can get a aftermarket rebuild with a 2 year warranty for less than $4,000. installed
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)