I was a travellling salesman (All over Florida) for a number of years. I knew several other salesmen who drove MB 240D 4-door sedans with 4 cylinder diesel engines.
Most would drive them 300K or more miles. One drove his over 500K, had the engine rebuilt, and sent his kid to 4 years of college (FSU - Florida's SECOND University) with it. They would get 30-35 MPG and smoke like crazy and were slow off the line.
But they didn't tear up and went a long, long, way with almost no maintenance cost. I would go through a Mercuy Grand Marquis every 3 years. Not very smart, moneywise, on my part when compared to buying a MB and driving it for 15 years or more.
I expect it was the cheapest transportation available, over time, in the US in the 1980's.
Florida ED