I have a 2012 C4S with a sunroof. When going over rough pavement I hear a distinct, persistent rattle -- more like a mechanical buzzing sound -- coming from the area of the rearview mirror and dome near the mirror. It may or may not be the mirror or something in the dome -- perhaps it is something under the headliner in that area -- but I am sure the sound is coming from that area (I have cupped my ears and listened and there is no doubt the sound is coming from that area).
My dealer observed the problem and thought he had fixed it -- by applying tape to plastic parts that may have been rubbing against each other -- but the problem persists.
Has anyone experienced this problem and discovered its source?