This is not a helpful reply, but....no....well not yet.
I had this issue with both the front headlight unit and one rear unit of my previously car (which was purchased new on a 05 plate, and so didn't expect this).
I have been keeping an eye out for this issue on my new baby, but so far (touch wood) its ok. It is such a pain that expensive unit casings cause these problems. To replace my headlight unit on a Nissam, as a whole, cost £200 just for the part itself. I am hoping that I don't have to do this on a VW, as I may have to declare myself as bankrupt

Please keep us informed with any responses from dealers (if you go to them) !