I was more referring to the 70s and 80s Mercedes. There is not a car out there today that can best the diesel engine from those times.
I was at a car parts place (a yard for recently totalled out cars) and there were several Mercedes 300E's from the 90s you could see that they were over engineers by ther construction. Even with the doors stripped of leather, etc, the doors slammed shut like a bank vault. The leather smelled like quality leather. And with the doors stripped, you see how they constructed them---very block-like...
I might even invest in one one day...
Mercedes used to over-engineer their cars, but when Lexus came on the scene, for Mercedes to compete, they stopped their budget---they were spending more to over-engineer their cars. In a announcement back in 2006, the Prez of MB/D-Chrysler stated that MB's quality would be back to standard.
My mom has a 2009 E350, and no problems (she hardly drives it, so that could be a reason).
Also, Volvo's were longevity kings as well. My dad had a 76 model that had over 250k on it, and this was in the mid 90s.