Mine initially made a noise which I thought was something loose inside the door. However, it turned out to be the trailing edge of the door rubbing on the bodywork, (and removing some paint in the process).
I had it sorted out by the dealer and all is fine now.
yep...it was a broken aluminium bracket that holds the base of the window frame to the door moulding, a dead easy fix. Simple to remove the door covering to check - just undo the 3 allen screws behind the blanking plugs under the door. 10 mins max, honest!
or....if its morew of a creak than a rattle (listen carefully) its teh door rubbing against the bodywork. Have a look round the aperture for rubbing marks. This is a very common fault, your dealer will re-ground the door edges and respray foc.
