Sound deadener

https://www.fatmat.com...... another sound damping you could go with.

https://www.mcmaster.com/ has a sound damping sheet, 12 sq ft @ $14.62.  Comparable to Dynamat.  See page 3270 and this is the line to look for under "Adhesive-backed damping sheets": 

Polymeric Mastic 0.070" 32" x 54" 0.10 -30° to +300° F 0.7 Black

14.62

stevdart is right, that mcmaster stuff is cheap.  However, it's acoustic loss factor isn't as good as products like brown bread, dynamat xtreme, raam, etc.  Additionally it is MUCH easier to apply any of the above mentioned products.  Peel, stick, roll. 

mcmaster stuff NEEDS a heat gun to stick. 

I don't know.  I applied it in 80 degree weather, had the sheets laying in the full sun, too.  It stuck to the sheet metal better than the Dynamat I applied back in March, though there was a 35 degree temp difference.  Def used a heat gun with that Dynamat!  I found, though, that there were still some edges of the McMaster polymastic that wouldn't hold well on a curve.  But a shot of spray glue on the metal made the adhesive seem like epoxy.

I don't know either what the difference is in acoustic loss factor is between this and the rest.  But I do know that my car could be heard a block away without the damping, and the rattling sound around the doors and trunk were obnoxious before I put it in.  Now, the sound will blast you out of your seat, but barely can be heard outside.  And no rattling, at all.  That, my friends, is acoustic damping factor in my book.

lol very true.  They publish those numbers for suckers like me. ;-) 

It has a bit of an asphalt odor when it is warm, installing it, but I have not noticed any odors this summer on even the hottest days entering either the cabin or trunk.  I have some Dynamat original in the car, too, and it is also asphalt-based.  If someone were to have stamped the Dynamat imprint onto the polymeric mastic, I wouldn't have been able to tell the difference between the two.  After I did the rear deck with the Dynamat, then had so much more to do, I was looking at having to spend about another $160 for enough Dynamat to finish.  But then I got a tip on this forum about McMaster-Carr, and instead spent $43 for it.  The site is very automated and they ship fast.

The damping doesn't have a tremendous amount of glue, but it is sticky.  Wipe the metal clean first of any dust, and in a few places I shot a quick light spray of 3M spray adhesive onto the metal for a better bond.  It has been covering the inside lid of the trunk now for a couple of months and there hasn't been any sagging or failure, but I did spray a bit of glue onto some areas there.  I just cut the pieces into workable sizes when installing, figuring if I ended up with some sagging the weight wouldn't pull it all down.  Because at the time I first heard of it I also heard from others that it wouldn't stick.  Hey, everybody, it sticks.  Just don't expect it to install itself...you'll have to give it a little help  :)

It goes much faster than I anticipated.  I ripped through a 36ft^2 bulk pack of dynamat xtreme and was only able to finish the front doors and under the rear seat.  I doubled up in places when doing the front doors if the spot still made a hollow sound when tapped.  I also matted the inside of the outer door skin.