overkill has been reduced in price and is now 19 bucks for 20 sq ft, much better option over the ebay stuff as it's the same price if not cheaper and already has the adhesive for easy application.
As far as using open cell in addition to the neoprene, I'm going to skip it for now as i'd imagine the area's I'd be able to use it are going to be limited and I have the lux liner if I need the extra absorption. Lets hope I don't regret my decision later and have to rip up the neoprene to apply the open cell under it. But i'm sure i'll be fine

 

ohh.. i bought 2 gallons of V3...

after my 1st coat in the trunk floor, it went on really thick, about 3-4mm...
after it was dry, went for a drive, wehn i get home i put my hand on the trunk floor to check the temp.... it was like room temp..

before when it was metal, i sware i could cook an egg, i remember it got really hot... like i could only hold my hand there for a few seconds..

so that little test by its self was enough to prove that it works as a heat barrier, or what ever you want to call it....

muffler noise was improved quite a lot, didnt do much for road noise, then again i had loud crappy uneven stock rubber at the time....

when it went on the doors, mid bass was improved noticably.

second skin = good

only thing it was pretty ugly to look at... as it is kind of hard to make look good and even because of its thickness....

so i got some 70sq feet of B quiet to go over the top...

 

I forgot you ordered the liner Bfish..you should be fine with that. Are you sure the Overkill has adhesive lining? I ordered some 6 months ago and it didn't??

 

Looks like your right overkill does not have an adhesive lining. What's the best adhesive to use to addach it to some sludge? Hopefully I can get something good stuff at homedepot or soemthing.
I think the stuff raamaudio sells can work. just wand to find it local.

 

I thought you were gonna go with Sludge, followed by Luxury liner, followed by Overkill? If that's the case I think the overkill will stick to the Liner better than the Sludge. I used #90 by 3M. It is OK but you have to spray bother surfaces and let it setup before attaching or it will only be a temporary bond. If you are in a high temp area or doing areas around the transmission hump I would recommend a higher grade, non-spray adhesive designed for high temps..I never found one :-(

 

Check out www.raamaudio.com they have a high temp adhesive they reccomend and sell. I will only be putting lux liner on high noise area's so the overkill will have to go on the sludge in most of the car.

 

Looks like good stuff. I wonder if you can find it somewhere local like Lowes since it is a DAP product?

Test it out on some dried sludge. One adhesive I tried seemed to disolve the Spectrum a bit and made it gooey. I would suggest testing in one area, let it dry and see how well it sticks before doing the whole car.

One thing that helped me with the Overkill was taking the stock carpet out of the vehicle, requires two cuts in the middle, and then applying the overkill directly to the underside of the carpet. This may be an option if you don't want to stick it to the Sludge on the floorpan.

I used open cell foam in the high noise areas much like you will use Liner. This was under the feet, under and behind the seat, in the cubby, and in the trunk.