It's probably the same problem I've experienced though it could always be something else. The plastic sheet on my left door isn't as taut and doesn't buzz. The noise is very reproducible but only if I play a particular song with a lot of bass. The sheet should be able to do its job regardless of how tensioned it is so I suppose it would be possible to redo it with less tension.

 

My passenger door steel insert rattles like crazy with bass. Anyone get the dealer to fix it?