Can I add my two pennies worth.
After 15 years of owning Landrovers Discovery's, we decided that we would like a change. We needed a 4x4 that could tow the wife's horse trailer and take my fishing gear on occasions. I also do my own minor servicing, so had to be user friendly. After a lot of research we settled on an ML270. As we were not that rich, up to 2004 MY.
We looked at about 6 in dealerships, two of which were Mercedes Garages, we were so disappointed, dirty cars, one was missing all headrests, one was a rust bucket, one would not start when we got there, another had a really tatty full respray. These were all cars with 70 to 80 thousand miles on, we were then thinking about staying with Landrovers, but we do not like the Discovery 3.
Thebut I saw an add, private sale, old boy had car from new, 2003, Mercedes service history, 35,000 miles. It was worth the 8 hour journey to see it. Clean, tidy, all up together. I paid £3950. Same as the crap at dealers. It's a nice car, we are very pleased. The only down side is no 3 months warranty.
I guess I am trying to say that sometimes buying private makes more sense.