My last Mercedes was a W210 E300TD. Great car that drove well, but the rust....ye gods. It's the one reason I won't buy another Mercedes, not even one that's fully galvanised. It was a straight 6 that was actually lovely and smooth, but recently I found myself in someone's Volvo V60 4-cylinder diesel and it sounded like a bus, just horrible. Getting back into my old LS was like stepping from the third world into Bill Gate's conservatory.
Plus, I do thousands of miles cycling each year and increasingly find that diesels stink to high heaven. I hate the smell; the sooner diesel becomes obsolete, the better.