I know there are a ton of options online, but is sound deadener sold in brick and mortar stores? I gotta take apart my rear seats and deck for some suspension stuff and it would be nice to sound deaden the rear deck at the same time.

On another note, would sound deadening the rear deck on a stock setup result in any worthwhile improvement?

 

I used a spray-able rubberized sound deadener in my trunk and wheel wells I got at Pep Boys. I think about $7 or so a can, used 3. Noticeable decrease in interior sound. Probably not as good as dynamat or something similar but for just over $20 I am happy with the results.

 

most audio and security shops should have it available for sale (at least around me they do). typically what's sold here is dynamat

 

It's good that you're looking in an audio store rather than a Home Depot like store. There is a very real difference in the automotive stuff and the roofing crap that some use. Many audio shops carry damper. One of the guys on here sells a very nice damper.

The main thing to keep in mind is a damper reduces vibration which is probably what you're looking for but it does not block sound. If you wanted to go the extra mile there are sound blockers that go over the sound deadeners. From Second Skin, their Luxury Mat and Luxury Mat Pro are sound blockers and it makes a very real difference in road and wind noise. There's a good bit of noise that comes through from the rear wheel wells and the shock mounts.