My E-Class Estate wheels are corroding - should Mercedes-Benz honour my warranty to repair them?

I have a Mercedes-Benz E-Class Estate, which I've had from new since December 2015. The front wheels are corroding from beneath the lacquer around the centre caps. As the lacquer is not damaged/broken I have concluded that the wheels must have been faulty when manufactured. The wheels have not been treated with anything since I owned the car and there are no stone chips near the corroded areas. Mercedes-Benz of Derby have taken a month to decide that 'the wheels must have been treated with something' and are refusing to honour the warranty. What advice would you offer in helping me to get a satisfactory resolution to this problem?

Asked on 31 July 2017 by Simon Hugessen

Answered by Honest John
Extremely common. Will be due to stone chips that you can't see that have allowed moisture under the lacquer. Utterly stupid ever to expect lacquer to adhere indefinitely to polished alloy and protect the alloy beneath. Alloys need to be painted before being lacquered to protect them adequately. Mercedes-Benz is countering that the wheels must have been cleaned at some time with an acid based wheel cleaner (hand car washes often use this for speed). That eats into the lacquer. All you can do is threaten to sue for the cost of refurbishment using Small Claims, but Mercedes-Benz may use the same defence in court.
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