made an even better solution. Take a piece of dynamat and cut a piece that is a long as possible (probably about 12-14 inches) by 1/2" wide. Roll a really really tight dyna-doobie with it. (if you heat the dynamat a bit, makes it easier, more pliable)

Then with your left hand (get into your contortionist mode) push DOWN on the top well. With your right, start at the center and work your way out....shoving the dyna-doobie into the crack. Get it as FAR as you can into the crack. This will make the top well SO tight, that it simply has no room to budge, nor rattle.

Did it on my car, and works like a charm.

P.S.

If you are a cheap bastard, and dont want to spend more than $3.00 on this mod, here is another variation.

Tube of silicone (black preferred, to match the plastic)
Smooth solid surface (piece of glass, etc)
Caulking gun (aka sausage gun)
Razor blade.

Pipe a 14" bead of silicone onto a smooth surface, and let dry overnight.

When dry, take the razor blade and seperate it off the surface, leaving a long spaghetti looking piece of silicone. Proceed with steps above.

 

Did you take the clips off before you push the well?
There was no way I could make any gaps with clips on.

 

Where is this well you all speak of? Got pics?

 

It's the big plastic board behind the seat.

 

any pictures of this?

 

Hmm, I wonder if this is what rattles when my top is up...

 

I wasn't able to make enough gap to stick some match or rubber tube.

So I fixed yellow pages between spare tire and top well.
Then I cutted the MDF and fixed it under left side of top well.
The rattles 80% gone and I'm very happy with it.

 

I cut a mat out of some rubber sheet shaped to fit in the 'well' of the shelf, then super glued some sub box carpet to the top side of the mat and slid it in place.

The weight of the mat stops any vibration and cuts out a lot of noise coming through from below too.

 

any pictures of this?

 

i need to do this i am tired of all that rattle