The more miles you will be doing, the more a diesel becomes a reasonable option. I had formed the impression you would not be doing much mileage, and it is low mileage on short journeys that militates against diesels.
Don't buy a car with Airmatic; it's good, but expensive to fix if it goes wrong.
That burgundy E240 (first one in post #16) looks absolutely superb for £2k, if you can live with the thirst, and there's a lot less to go wrong than in later cars. Find one similar with a diesel, and the same applies, plus the economy will be much better. The inline six-cylinder diesel engine (OM648? OM613?) which preceded the V6 in the early W211 is regarded as one of the best (and most bombproof) diesel engines MB have ever made, and more conomical than the V6 as well.
Looking at diesels, bear in mind anything in emissions class euro 5 or lower is likely to incur daily charges in the increasingly common low emissions zones in city centres.
I had formed a similar impression. Perhaps it was the phrase "I don't do long journeys" in the opening post which fooled us?!
Yeah this is the quandary I have, these days I don't do many miles, I always quote 5k for insurance, but not that I track it, my days of doing 1000 miles in a weekend are behind me, But, as I mentioned further down my daughter is\was (well will be past thence soon) a 100 mile round trip, and what with looking after her first child while they were in ICU with the new baby after it needed emergency surgery clocked up a few miles, but I had to use her partners car so it could have been a lot worse in my car, and there were mentions of moving to Scotland, hence considering diesel, it's only 8 hours drive dependent where she has in mind.
But the bombshell dropped tonight, they have sold their house (waiting for pen on paper to seal it as is standard), and they are going to spend a few days\week at Xmas house hunting in Scotland, well to go to the ones they have shortlisted, so the MPG deal is more so now.
I don't know if the charges will affect me or not, I don't go to London much since being housebound, and toll charges and red zone (can't think of the name) charges I am exempt from, it's not an absolute coverage, there are still plenty of times you do have to pay, but not in London for me, but yes I do have that well and truly in mind with the emissions, Damn Mercedes having easy entry\exit seats, it's the main reason I'm trying to get a Merc, I can feel my legs melt away when it moves into position, so this more than anything is the cherry on the cake, if it weren't for this I would not worry about Merc's as much, I had never heard of it until I drove an S class along with the soft close doors, then I stumbled on this function in my car, I doubt the dodgy trader even knew about it, so it would be a dream to get this in the next car.
Well many Thanks to everyone, it's helped a lot, sorry I haven't responded with quotes for specific answers, but my head struggles to keep them separate when replying, and not repeating myself where a couple of people made similar comments, my memory span is that short, so please don't think any answers have not been appreciated, it's just easier to roll down the list as I remember bits, I'm going to have to take a couple of days searching with your valuable input, and see if I can come up with a short list for checking, if only other cars had this seat function I'd be over the moon, but Thanks again everyone, it is helping.