Can someone show me what he is talking about because I can’t see the pictures or the video in the link. Thanks.

Pictures are long gone. Pieced together what to do from Taz’s post. I’ll copy it below....







He explained that the rattling was the "baffles" releasing extra air from the heavy excursion of big bass songs.

I have a 07 TL, and i started having this sub. rattles two weeks ago, and i tried padding the hole around the rear vents area, and still have some other thing rattles, so i find out the other rattling from the right side seat belt holder(the mounting bracket). so i fixed that too and now is fine!!

Okay so i did this yeterday night took 15min to do, i broke 3 screws i ripped the truck cover thing off. And i put pieces of towel, by the vent area. And then some rattles went away. Then i went in the back seat and i heard alot of rattle coming from the red back light in the top of the ceiling of the car right, its right on top of the middle seat in back. And i pushed up on it, and the alot of rattling went away. But when u stuff it up in there, ppl see it clearly if thier behind u in traffic. U could try superglue. Or some kind of clear drip free glue. But now the sub rattles like hell. And the only way to fix that is get a better quality sub. This stock sub is no good. If i turn vol-7 it rattles so bad even with the bass down to a little more then half.

I believe the sub is not the problem. The problem is the plastic vents smacking the rear windshield. As for the purpose of the vents... could they be ports for the bass to *exhaust* it's sound?

I have 05 TL that I've had this problem for about a year. The dealer wanted to charge me $110.00 for labor just to look at it because my warranty had expired! I just removed the cover with no problems and didn't break any clips. I wedged something between the vents which seemed to help but I still had an awful rattle/vibration. After investigating further and the real point of my post is...My rattle was coming from the GPS antenna which sits next the subwoofer! The antenna can be easily accessed through a hole and when I would put my hand on the bottom of the antenna the rattle would stop. The only thing that I could think of doing was wedging a piece of cloth between the antenna and the frame. Everything sounds much better now!

FYI...just performed this fix on my 08. The rattle is actually coming from the rear vent vibrating against the metal deck underneath. Worked like a charm.I actually used some strips of 1/2" closed-cell foam that I had lying around from a sound proofing project several cars ago and it worked quite well. There's really nothing too it, I used fingers and a screw driver to wedge it in there.

Thanks for all the info guys - I actually used the advise and come to find out... its NOT the rear vents that are vibrating - its the seat belt mechanism that sits right next to the sub and supplies the seatbelt to the middle passenger... I apply pressure to it and it and the rattling stops.

I just fixed my rear deck rattle. It wasn't what the OP found. The noise I was hear was from the plastic door that cover the metal hook for the car seat in the center. I had some Crystal Method playing and pushed up on everything in the truck and it didn't stop. I went inside and pressed on the speaker itself, still no fix. I then opened the plastic door and it stopped! I stuck some weatherstripping in there and closed the door, ALL FIXED.

I also found out the plastic cover for the child seat hook rattles I stuffed that with some cloth and closed it and it no longer rattles.

yes it worked! First I put Drake song on repeat with max bass and max sub. Then I stuffed high density foam between glass and rear deck with a flat head screw driver. That actually made the rattle worst. So I knew it was something else.
Then I removed the trunk covering to see what’s making the rattle from under. Turns out it’s the middle seat belt assembly. I could see the components vibrate inside of it. I tried to pad it without success so I got fed up and destroyed it by removing the plastic covering and took out all the small parts.
That fixed my problem but the middle seat belt is not functional anymore. Since I use my speakers daily vs the rear seat belt almost never, in happy with the result.
Good luck!