I noticed this as well with my car. It has something to do with a pressure change. I noticed though, if u open the sunroof and then open the windows for a second and then close them again it will not do it anymore. Give it a try it worked for meNH_FAST said:Hi, I have had my Magic Black MKV for about 3 weeks. Today was our first NH nice day and I opened the moon roof. From my other VW's I know that if you open it all the way w/o cracking the windows it makes a helicoptor sound. What my MKV is doing is it vibrates the roof if I don't have the windows half open. This happens if the moon roof is open more than half way. Has anyone experienced this? I wanted to check out there 1st before complaining to the dealer.