Good service response Peter. Nice to hear that MB have stepped up to the plate on the issue at hand.
My wife has had MB cars for the past 14 years (one for 6 and the latest one for 8 years). Both cars have been extremely reliable and when they have had problems these have been dealt with quickly, efficiently and courteously; repair costs have (perhaps surprisingly) been competitive with MB either picking up the tab, contributing or, at the very least, offering a discount.
Having the cars serviced by MB means that she gets a range of fringe benefits including free breakdown/recovery and an MOT guarantee (the latter tested this last year when she needed new brake lines - total cost was around £700 but MB picked up £500 of that).
When she wants to use the car abroad she turns up at the local MB garage and they adjust the lights for her on the spot; the same on return. Whatever the issue, she simply goes to the garage and a mechanic/technician comes out immediately to check out the car. I took my Subaru into my local main dealer once with an engine warning light showing, they told me that the earliest they could look at the car was in 10 days time and would I like to book an appointment.....'should I use the car meanwhile?' I asked....'up to you but we really cannot advise on that without inspecting the car'.....chalk and cheese really and although I really liked my Subaru I couldn't put up with the dealer's attitude and replaced it with something else in the end.
Service delivery does of course vary between marques and dealers and (stating the obvious) all cars will have issues at some time or other, but for me it is the way the issues are dealt with that make the difference in the end. Others could learn from MB's example.