I have both cars and they both share the same problem, worse on the
300SD. The power sunroof opens very slowly and closes slower, and getting even slower with time. We're talking slow! I'm almost afraid to open them now for fear they won't close again. I have no experience with sunroofs previously so I don't know where to start or what this might be a symptom of. Failing motor? Lack of lubrication somewhere? I did try WD40 on the slide rails that I could reach.
Thanks for any help or direction.