I recently noticed stains on my headliner. I was having issues with sunroof seals, and electrical problems. After going to several dealers with these problems I found one that fixed everything. Including replacing my battery. The dealer where I bought the car claimed to have replaced my entire sunroof. The next said there were no problems. The third (when I noticed the stains) replaced the seals unclogged the drains shampooed the headliner. The third dealer also got to the bottom of my electrical problems.
It pays off to try different dealerships to find the best service.
BTW I did make several calls to BMW NA through out this process. I think that all of my documentation was helpful when it came to them stepping in to rplace things that weren't covered under the warranty.