This is driving me crazy. I can't figure out what the heck is back there rattling, but have any of you guys had problems with this in your sedans? Something back that way rattles pretty much non stop if the car is moving. It's not in the trunk and the only thing I can find back there that really moves is the headliner.

 

It's probably the rear deck plastic (the black speaker cover piece). Mine rattles like crazy, especially when I have loud music on.

 

remove the speaker covers, see if that makes it go away..

 

Do they just pop off?

 

Do the center one first and then the sides. Yes the pop off. Its a pain to put the center one back on properly.

 

my si coupe rattles as well it turned out to be the cover on the child seat thing. Used some clear tape to solve the problem.

 

the rear speakers are just held on by a clip. but i dont think its that. when i put my system in everything rattled to ****. so a cut some styrofoam from my subwoofer packaging and tucked in on each side of the rear deck between the deck and the rear window and a little piece under the headliner. worked like a charm and the rattle was gone, at least on the inside of the car. soon ill figure out how i can get my trunk to shut up

 

My wifes 07 had this issue.If you still have warranty take it back to the dealer.If not,remove the rear deck lid(be sure to buy new clips to ensure a tight fit afterwards), and install some dampening felt stripping on the underside of the rear deck.That what Honda did on my wifes.Haven't heard it ever again.