... I got another phone call telling me they'd done a safety check on the vehicle and I needed two new front tyres and new break pads, along with new wipers. Well now if a car needs all of the above, is it not safe to assume that the car is due a service!!
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But the items you mentions are not part of a standard service anyway.
A standard service would usually consist of oil, oil filter, sump plug & washer, fuel filter (diesel), air filter element, pollen filter, spark-plugs (petrol), checks on coolant and hydraulic fluid levels and either topping these off or replacing them if its a major milestone service (every two years usually).
Tyres wear at different rates dependant on whether they were kept properly inflated, whether the suspension or steering was damaged by a pot-hole or kerb and on the driving style of the driver (enthusiastic / conservative). Brake pad (and brake disc and even clutch) wear are also effected by driving style and indeed competence. Similarly wiper blade wear depends on how often and in what way they were used (ice, snow, rain, dust & bugs in summer).
I am not defending the charges for replacing brakes, wipers or tyres, in fact I find the charges staggering, but these items are never part of a standard service.
BTW, what was the 50 quid for? Was it a tip?
I would guess you went to a BMW dealer - bad idea for the "consumables".