Another thing is that my hatch i just closed the other day and when it closed the interior plastic trimming all came loose and fell into the trunk. I had to open it up and snap it all back into place and now i'm getting horrible vibrations when i go over bumps. Maybe one of the fasteners is worn and not catching properly. The reason i'm stating this is that if the rubber stoppers don't seem to be the problem look into the inside of the hatch where the plastic molding trim is and feel if it's loose or wobbly.