So it's actually rattling against the rear window, and not against what's underneath it? Interesting.... That would mean that putting foam under it wouldn't make any difference.

 

I'm not sure if this helps, but I thought my rear deck was rattling. Tried stuffing all kinds of stuff up through the trunk. Put felt along the back edge. I think I finally found the problem, it was in the passenger side C pillar. When I pulled off the cover, there is a round metal clip about half way up I believe around the air bag, It was rattling against the frame. I bent this a bit away from the metal frame and no more rattle. Might be something different than your rattle, but it sounded like the rear deck but was actually behind the C pillar. If it comes back I'm planning on putting a little felt behind it.

Jon

 

i went to the dealership today about this and a recall i had, he said he put some stuff under my rear shelf to stop the sound and that didnt solve the problem so i left because i didnt have much time but im going to investigate this more today and try to figure out the exact location, im gonna check the spots u guys suggested

 

Off topic but good, I'm glad you are fighting with them. I walked away from them when I was looking at buying my X.. everything there gives off a slime vibe to me. Maybe others had better experiences. Let me know if they fix this for you..

 

Dealer is having some stereo shop do some work to the car today to fix the rattle. We'll see how it works out...

 

when I had my x I had the same problem with the rear shelf rattling between the glass and whatever is underneath. I used some weatherstripping from home depot that is for sliding glass doors. its about 1/4 inch thick. I sandwiched this between the glass and the shelf and it really helped a lot. I spend a whole weekend hunting rattles lol.

 

I diagnosed mine to the sub enclosure rattling... something inside is loose

 

Well, the dealership hired some dude and paid him $50 to come in and stuff a couple pieces of foam between the plastic and the window. What's funny about this is that I specifically told the dealer that the plastic was NOT hitting the window, and that the sound was coming from underneath. Well, it didn't fix the issue, obviously.

So, last night I pulled out the rear seat and popped up the rear shelf. I stuffed a couple of rags in specific areas, and now the rattle is gone. about 45 minutes of my time and it's fixed.

Proof that if you want something done right, you do it your fu*king self.

 

That and dealership monkeys that work in the shop are retarded.

 

This car loves to rattle

 

Mine rattles too... ill work on fixing mine eventually lol

 

Mine doesn't rattle anymore. I put some sound damping material up there, and added a bit of other filler, and it it silent, even with my new sub.

 

My 09 ES with the Rocksord Fosgate also rattles and it is the real deck.. i'm going to try your guys suggestions to get it fixed. my 2010 didnt have this problem at all i could turn up the bass passed 3 and it would be fine.

 

See, that's what I'm sayin. Very inconsistent. Some cars do, some don't.

 

I also ended up having to fix a few rattling issues but I think I have a rattle still in that same place. It sounds like there is something loose in the sub enclosure.
Have you fixed your issue? If so, PLEASE tell me how you did it!