Mercedes-Benz C-Class coolant problems

My Mercedes-Benz C250 CDI W204 is four years old with just under 32K miles on the clock. Yesterday it came back from its service and the dealer informed me I have two coolant leaks on the engine. Water pump and Thermostat housing. They highly advise I change both, at significant costs. The dealer says Mercedes-Benz will give a 50 per cent reduction on the water pump work as it has failed earlier than expected, but the thermostat housing is at full price for some reason. None of this was a problem at last year's service. To fix both these issues at the same time will cost about £550. What should I do?
Well, you could claim under sale of goods that the parts have not lasted the six years your could reasonable have expected from an expensive and prestigious consumer durable: Not 100 per cent confident that it is worth taking on MBUK for the sake of £550. Meanwhile I'll note the faults in car by car.
Answered by Honest John on

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