Cheers for the picture. Looks pretty shocking. I'll keep my eyes out as I assume the 19s are just as sussectible to this as the standard ones.
Any polished and lacquered finished wheel is susceptible. If this happened out of warranty, I would get the wheels painted or powder-coated.
Some dealership warranty managers won't entertain a claim, some bottle it, thinking that VW won't reimburse them. Happened to me, Benfield wouldn't touch them, despite me showing them many of their 2nd hand stock being affected and with no kerbing. Pulman replaced them without bother.