I had an 05 S class. Great car, smoothest thing I ever drove. I remember driving home from a college game one night in the rain years ago and my passenger who didn't like speed, said he thought I should slow down. I was cruising at 105 and didn't realize it, thought I was doing 70. These things are made to go smooth and go fast. The problem, however, and you will have problems, is what you hear - they are as expensive as hell to repair. I had an indie mechanic who I trusted and even though he was about 40% less than a dealer, I would still get bent over. I blew a fuel pump (actually I think it had 2 but am not sure) and it was about 900 to pull it and replace it. Any little thing would cost a fortune. The regulator for a window? Outrageous but at least I had a body shop friend I barter with so it was replaced labor free for the cost of the item, about 400 aftermarket. You had better use their fluids, also. Don't know if you could get away with something other than original, but I never did because my mechanic would not. Brakes were a fortune. There are a few forums out there where you could get help, for example when my automatic door shut regulator blew. I did not want to pay about 8-900 for a new one, so every now and then I learned I could open the trunk and pull a fuse 11, and once again my doors would shut completely - for a few weeks until I pulled/inserted the fuse again. Same with the trunk closure mechanism. Blow or crack a head lamp? Bend over or get an aftermarket one that looks like shit. Yes - the absolute best, smoothest ride ever, and I mean ever. But I will never own another. Too much nickel and diming (well. maybe 100 and 500 ing) to make it worth it. Good for a few years, but hit 50,000 and start having issues. I was told there was some sort of AC mechanism that sooner or later was going to go bad, and it would cost 5-6 grand to replace. I had my tranny replaced under warranty at I think 60,000 miles. Are you kidding me? Ten grand that I did not have to pay. And remember, an S class is one of the premier Mercedes, the flagship. But loads of problems. Loads of fun for sure, man what a great car but it wasn't worth it. Plus, the forums for Benzes are filled with many dickheads, in fact more dickheads than helpful people. You wouldn't believe the crap that would go on there when you sought help. We have a rare breed with this forum for sure. Want to feel like a moron? Go on a Benz forum and ask a question! The only good thing was about the time my mechanic said I really needed to think of unloading it (the AC was overdue to go) I was stopped in traffic, waiting for someone to turn left. Looked in my mirror and saw some jackass texting. Thought "Oh shit - he doesn't know I've stopped" and boom, he hit me at about 30 mph. I thought for sure the car was totalled. I got out, surveyed the damage, and being 100 miles from home knew I had to drive home, so took a crow bar out and bent some metal back. Driving that beast home from inside the vehicle you would have no idea that the entire back end was destroyed. Like a Volvo, this tank was built to survive an impact like that. Interior intact, and we drove home. Took it to my friend's body shop, and made sure it was totaled. Did my lawyer thing and made them give me a Mercedes rental for the time the case was under insvestigation. Got a Mercedes SUV for a few weeks, forget which type. This thing was a complete POS. Driving this low end Mercedes SUV which I'm sure sold for about 60K at the time sealed my decision that I would never own a Benz again.
Back in 92 I bought a 90 BMW535I. That was the baddest car I ever owned. 5 speed, handled like a dream. Not smooth like the Benz, but it was a sports car. Eventually I blew the engine on it and had to get rid of it, but that was the funnest car I ever drove. Pure speed and maneuverability. Downshift and adios. But even the newer BMWs are fraught with issues. It's just amazing that you can get a Honda and have it go 150000 miles before you even get a hint a slight trouble. Sure they don't ride like a Benz or BMW, but those days for me are through. Back then I drove to impress, or so I thought (in the lawyer business). Now, I'll show up in my 12 year old pick up truck and woe to the fool that misjudges the redneck in the pick up truck.
Bottom line? Don't buy. You will eventually regret it, unless you have a few years of the warranty left. Imagine if I had to pay to replace that tranny ? Yikes!