I think the real problem is that MB and its dealerships seem to think it's perfectly acceptable to quote someone £330 for a B Service and then inflate the bill to £900. It's a con. How many people, who are running cars with their own money, would cheerfully take up the offer of a dealer service if they were quoted £900 up front. OK, hawk20 would, but who else?
Rory, you really are letting your relentless anti-MB anti-dealer stance, lead you to say things which are irresponsible IMO.
Dealers have a duty of care. Cars are complex lethal weapons. If you go in for a B service, for example, and they find your brakes are worn and need changing, they SHOULD tell you. And if the brake fluid needs changing, they SHOULD tell you. And you should be glad. And should want matters put right.
This is not inflating the bill. It is telling people what needs doing. If they don't take the advice and have it done, I'm glad they refuse to stamp the book.
Anybody who cares and takes a tiny bit of trouble in the care and maintenance of their car can find out what jobs are needed and when. Brake fluid every two years and so on. Plugs changed at 50k and so on. Either get it done before you go in for a service or be glad they tell you it needs doing and require to do it before stamping your book. It would be irresponsible to send someone out with inadequately maintained brakes and yet with the book recently stamped. Or with plugs past recommended mileage and then expect free Mobilo to tow them in if they break down, wouldn't it?
The fact that so many are surprised to find that the plugs need changing (when they happen to be in for a service) tells you something about those owners. Why didn't they know? Would they ever have changed them if the dealer had not brought it up?
Basic servicing costs the average customer on average miles about 2p per mile. People should budget for that minor cost of motoring. They also need to do a tiny bit of sensible planning to decide whether the other maintenance jobs on their car will be done by a main dealer or by an indie. Not that difficult is it?
The truth is most do not make enough effort. Loads of cars come in for service, with illegal tyres, worn brakes, low oil because nobody has checked the oil level since the last service, and numerous other examples of people not looking after their cars properly. Thank goodness that responsible dealers do tell people what extra work is needed and ask them if they want it done. Nobody has to say yes do they?