Purchased this for my wife with only 20k 4-years ago and the car has been great except the transmission.
The 722.6 transmission was problem in the older E320 and still is.
The TCU connector seal failed which Mercedes had an updated part but then in leaked later on also.
Read some forums and I'm not alone.
Even the new 722.9 Transmissions are having issues.
I have owned 4 Mercedes and all the transmissions have had issues.
Love the ride, the style and interior layout.
Great room for the dogs.