I own a 2010 Mercedes C350 CDI with AMG wheels which are coroding under warranty from the centre out. But Mercedes only offer the option of replacing 3 of the wheels if I pay for one at £700 each because of minor curbing on one front. The kerbing has nothing to do with the damage and I have offered to have it repaired, or the fronts ignored but Mercededes will not budge.

Surely a warranty has to replace faulty parts and if there is an element of beterment due to normal wear and tear that is normal.