Hi guys, I've posed this question in some of the facebook groups but I wanted to get some opinions here as well. There's a rattling/sliding noise coming from behind the passenger compartment in my car. When I go around a turn, or accelerate or brake sharply, it sounds like something is sliding around on a hard, flat surface. I went to the dealer, and we thought we found the problem- there was a loose washer sliding around underneath the floor in the boot, but the sound is still happening. Does anyone else have any experience with this?