Sound Damping

Finally doing the install after waiting 4 years.  Ripped apart the car to find some very large voids between body panels and interior panels.  Plan to fill them with Polyester or Polyurethane Foam, but I am not sure which will yield better damping.  Or if anyone else has any other ideas on what I can do to fill the voids, please fill me in.  One other thing, has anyone replaced the seal on their trunk.  I already lowered my striker plate and used a body hammer to raise the lip on the trunk seal.  The trunk still has some leaks and resonances I need to take care of.  The car is a 99' Solara just in case anyone has had any experience sound damping one.

To fill A-pillars and other gaps like that, I use Dap minimal expanding foam. It comes in a blue, white, and black can. The great stuff in the orange can expands violently and can cause sheetmetal to buckle. I like the B-quiet Extreme on www.b-quiet.com . I found it best with any dampner sheets to apply it on a cool surface (I mean like 50 degree surface) and use enough heat from a hair drier to make the tar gooey (You will feel it when you press it out). Be sure to really push the stuff down in all the little recesses and cracks etc., like illustrated on my floorpan deadening example.

When I say voids I am talking about areas with about 1 cubic foot of space between body panels.  Main place I found these is behind the drivers doors, there are large empty cavaties letting in sh*t loads of road noise.  I have already used the expanding foam in the smaller places.