When I first got my Solstice, one of the things I enjoyed was how solid the structure was. Close the door and there was a solid thud. But as months went by, that thud took on an added almost rattle. It was only noticeable when I closed the door and it was on both driver's side and passenger's side. I thought there was something loose inside. But this had me puzzled because (unfortunately) the passenger's door is rarely used. I mentioned it to Tweety (our expert on latch mechanisms

) and he said there was nothing in the area of the noise that could work loose.
Cut to the chase...
It was the outside rear view mirror. More specifically, the mirror break-away swivel. The two painted surfaces were rubbing and creating a kind of creaking noise. Fix was easy. Just pop the mirror out of the way and put a drop of lube (grease, oil, silicone) and twist it a couple of times to work it in. Door sounds like new for free.