So I had a slight rattling sound when going over bumps. It would drive me nuts. Couldn't figure out if is was coming from the rear shelves of the spoiler. So I finally took it in and they heard the rattling noise and it took them all day to find the noise. The motor mount for the moonroof in the headliner was vibrating against the headliner itself. they has to add an felt adhesive pad against the 2 and now the car is quiet as can be. Amazing how much of a negative effect a small little rattle can have.