Occasionally, I hear a bumping noise coming from the rear when hitting expansion joints or other road bumps. I've noticed the trunk liner beneath the package deck has a lot of "up and down" movement yet appears to be installed correctly. It has a series of small black rivets…holding it up yet it bounces up and down maybe 3 – 4 inches. I once had a lot o luggage in there and wonder if I jammed it up and caused this looseness. Does anyone know how to remove this liner?? It is the piece below the rear window.