Check the mount with the single torx like bolt with door guide arm in it. Mine was loose and sounded horrible. It is locateed about have way down between the hinges.
I had the same problem and it will get worse. The guide-arm bolt is loose, but so far I have not found the right tool to fix it properly. It is not a Torx. A big Torx helps, but I guess I will eventually have to go to the dealership.