I thought my sub was rattling too. I folded down the rear seat backs, pulled the carpet insulation, and found a module behind the rear center console (close to the floor) that was very loose. Its only held on by a plastic push clip. The module vibrates with the bass making it sound like its coming from the sub. I cut a piece of 3m double sided foam tape and installed it behind the module and pressed it into place. No more rattle. I then opened the rear doors, blasted some music, and found where the vibrations were on the door panels. I used a plastic pry tool to lift the panel slightly off the door, put double sided foam tape in, pressed the edges down, and no more noisy rear doors.