I am the original owner and bought it new in 2000. I mainly use it when I need 4WD or hauling so it still has only 75k miles. The engine, transmission, and brakes are great and have never needed any service, but the rest of the car is junk and it has problems that are characteristic of this model and year, as noted online by other owners. Mercedes will not admit or correct them since they emerge after the warranty expires. 1. This wagon is prone to rust around the fixed rear window in the rear hatch. I had to have it fixed in a body shop for >$600. It affects about 1/3 wagons, but you don't see that as you drive around anymore because most of us who still own ours have had it fixed. 2. The CD player in the rear wheel well has problems with the transport mechanism. I had it fixed twice at my expense but it kept jamming so I gave up and don't use it. 3. This model year had terrible (and known) problems with the insulation on the wiring under the dash. Mercedes used an environmentally friendly material that broke down prematurely and the wires shorted out. My dashboard clock and outside temp. readouts have been useless for years. It would cost thousands to get under the dashboard and replace the wiring, so I just stuck a cheap digital clock on the dashboard. 4. The releases on the rear seat backs that allow them to flip down have an elaborate cable linkage that broke (at different times) on both rear seats despite little usage. (If one broke it could be bad luck, but both breaking means there was a design flaw.) 5. Both rear window regulators failed (at different times) and had to be replaced because the rear windows would not move. 6, The volume control knob on the radio doesn't work properly so I use the + and - buttons on the steering wheel. 7. The on-off button on the radio has stopped working reliably, so I often just lower the volume with the steering wheel button, instead of turning the radio off. 8. After only 60 K miles the car needed new shocks. Mercedes shocks are Bilsteins, and for this model I was quoted $2,000 by Midas, not by the dealer who would surely have been higher. I'm not putting that kind of money into such a flawed car.
Problems #1-4 are well know to Mercedes owners in chat rooms, but Mercedes will not admit any of them or correct them. I keep the car because the engine and transmission are flawless, the cargo capacity is enormous, and the 4WD is essential in the snow. I would never buy another Mercedes and my daily transport is a 2014 Lexus ES Hybrid. Toyota products are absolutely flawless - I've owned two Priuses, a Camry Hybrid, and now a Lexus Hybrid, and have never fixed a single thing on any of those technologically complicated cars. They have all been passed down to my children and grandchildren and are still in the family with high mileage yet remain flawless.
I bought this vehicle with 132K miles on it from a mechanic that had owned it for 5 years. I had it in my possession for a little over a year. The main reason I bought the car was for transporting my road bike. In terms of functionality, it performs admirably, the wagon bodystyle is very good at hauling around the road bike and makes Costco trips a breeze.
Performance - The engine power is adequate and the transmission shifts smoothly.
Fuel Economy - On the highway you can achieve near 30MPG with cruise control; however, city mileage is near not so pleasant, 12 or 14 MPG.
Handling/Ride Quality - Handling is okay and ride quality was a bit floaty.
Cargo capacity - The wagon is large and performs better than many SUVs for hauling purposes.
Tech - I was pleased to find that this 2000 model year had a relatively good navigation system (with traffic) and Bluetooth, pretty high tech for the time.
Third row seats - These rear facing seats are GREAT, the owner's manual says persons under 5'3" shouldn't sit back there; however, I have driven guests around that are 5'10" and have been more comfortable than a SUV with three row seating.
Reliability - When I took owenership of the vehicle it was in VERY good condition, but over the first few months small electrical glitches surfaced.
The on board computer would say that a bulb was out, but all were functioning.
The computer would also say coolant was low, but it wasn't.
The vehicle also began to develop an odd thumping sound from the rear suspension that was too intermittent for a proper diagnosis.
When I downsized from having both the MB Wagon and Lexus IS, I would have kept the wagon if it weren't for the MPG and the weird electrical issues.
I purchased this wagon with 82k on it and now it has around 117k. It has had a few repairs, but nothing truly outrageous. It drives very well, especially at high speeds on the highway. This wagon can take on 85 mph all day. I have averaged about 21 mpg, with about half highway and half city. The 4Matic AWD is truly a dream. One nice touch is the third seat. It's not habitable by adults, but my children think its a novelty to sit in a rear- facing seat. One maintenance item to watch out for: the rear window regulators WILL break, and they are about $400 to replace from the dealer. Try to find a European auto mechanic rather than always bringing it to the dealer.
Dealership is just a total rip-off, some reliability issues. Cupholders are horrendous. Many of these cars have a tendency to burn oil. Mine goes through about two quarts every five thousand miles. Fix the window regulator issue.