I had the same problem with my drivers door. Took it into my dealer and they took it off me for a day, stripped the door down, refitted the panels with some extra inserts and now there is zero rattling. Ask your dealer
What problem did you have, vibrating with music or just the regular door card vibrating?
I don't have the door card issue that others seem to have, my speaker just sounds like those portable walkman speakers that were overwhelmed by more than 10db of music
To top that off I'm now getting a high pitched vibrating which I'm not sure is the sound actuator coming through the speakers or something from under the central dash speaker cover. I've taken it off and I assume the small board under there is the GPS?
For a one year old car the build quality seems pretty shocking. I don't think I will be seeing more than 2 years ownership at this rate. Defo the worst quality VAG car I've owned.
I'm loathed to book it in at a dealers as they are as much use as a c0ck flavored lollipop.