I just got my 2006 E350 4Matic and so far, things are going great. I love the power shade, the quality of the standard stereo system, and the integrated 6 disk changer. The 4matic seems to have a little trouble choosing gears but that may by own perception. I love the distinguished look of the car and the maturity level it portrays since I'm only 28 and use the car mostly for business.
CD changer, power rear shade, all- wheel drive handling, power, looks.
Passenger seat belt warning light goes on even when there's no one in the seat.