Two negative things I've noticed...

[f5fstop]

When max base, push against the door panels to find out where they are vibrating, then remove the door panel and place some stiff foam behind that area and do it again.
Took me about five times (for each door) with a Corvette to stop vibrations in the doors, due to the Bose reverse cone woofer in the doors.
A dealer can do the same thing, but knowing dealers like I do, I would prefer to do the same thing myself.