I noticed when cleaning mine yesterday, there's the ever so slight beginnings of the old white-worm. Just on the edge where the rim is turned, it appears to be bleeding under the lacquer.
The car is just over 2 years old, so I'm not worried about getting them swapped ASAP.. but how far do they have to have gone before VW will agree to swap them - Will they swap on a little corrosion, or will I have to run around with grotty wheels until they're bad enough to be deemed worthy of replacing?