So, I guess the previous owner knew what he/she was doing with the amplifier and had removed the liner, adjusted the output, and put it back in. Nothing is out of place but the bass hits hard enough that the top and left side liners are now rattling heavily. I've stood up my helmet, shoes, and my owners manual leather case to hold the top liner still, which seems to fix the problem [Holding the liner physically in the center stops the rattling when the bass hits as well].

Any ideas how to fix this issue? Has anyone else knocked their liner loose with the stock Bose system as well?

 

The trunk lid or inside the trunk itself??

 

Inside itself; the liner underneath the stock subwoofer, and the left side of the trunk interior as well.

 

need to find the points that rattle, and put some tape, or dynamat or something between the contact points to insulate it.