haha cookiemonster i logged on this morning to write pretty much the exact same thread!
i had my car in yesterday to have the headlight washer fixed under warranty and i asked if they could have a look at my wheels for the whiteworm. i had noticed a very small white mark form a month or so back on 1 of my wheels, on closer inspection i noticed that as luck would have it it was on the same wheel i had slightly curbed a while back (wasn't holding out much hope for a replacement).
The guy called me up a few hours later saying everything was fixed and he had ordered me a new wheel and 4 new centre caps , no probs at all
very pleased as i was always nervous that i would receive 2nd rate service from the dealers as my car is an import
edit: forgot to mention that this was Rdigeway Reading that have been so helpful and it was the service manager (James i think) who i was dealing with.