rear deck vibrates

[nismo1219]

ok, i just recently got my speakers and headunit installed last weekend. however, when i picked the car up they didnt even pull the seatbelts thru the back seat! plus, now im getting vibrations from the rear deck even when the radio is off. i think the vibrations/sound of my exhaust is causing the deck to rattle around. possibly it wasnt skrewed back down or something? anyways can anyone give me a write-up or someting on how to fix this??

[MinisterofDOOM]

The rear deck upholstry snaps in place with plastic clips (the same sort of plastic clips that hold the door panels). Just make sure they hooked them all back down properly.The rear lip of the upholstry panel slips into a sort of notch.