You really need to read this entire thread. Frost King has been discussed numerous times prior to your post yesterday.

Some people have posted up bad stories about this stuff not taking the summer heat well, and basically melting inside cars, creating a stanky goo that's basically impossible to get rid of. I guess only time will tell for you if it's true.

For me, why waste hours of time, hours of being uncomfortable, and the chance of mucking up your car, just to save a few bucks? We are not talking about the difference of $1000 to $100, we are talking the difference of like $150 to what, $50? That's just being cheap. See my post just above for more thoughts on this, and how I myself was cheap about this.

In my case, I bought the FatMat as well. I figured for ~ $40 I could cover the rear hatch area and well wells and down to the rear of the seats. I barely had enough to complete my job.

Additionally, I bought a $8 can of undercoating took off the rear wheels and sprayed the inside of the wheel wells.

It just so happened that I live on a street that is coming apart and the tiny pebbles were driving me crazy coming to and from my house.

My problems with road noise was only the tiney sound that the pebbles made hitting the undercarridge and wheel wells. If I'm on a road that allows me to go faster than 30mph the rocks seem to fly out under the fenders before they can even make a revolution and therefore no contact with inner fender wells. That's a good thing.

I'm glad to say that three hours later and $50 I'm pleased with the results. The sound hasn't completely gone away but, it sounds much more pleasant now. A dull thud vs. a high pitched and vibrated ping. I know it sounds like we're making too much of this but, it's not something I'd expect in a expensive street car. Something I expect out of a cheap econobox or in a race car or track car you expect it. I know why Nissan did it but I don't need the 20lbs it saves me on this item. You can still hear tire roar and tell the difference between road surfaces but, that has improved somewhat as well.

I took couple good long trips on the freeway and back mountain roads this week. Those roads had a lot of pot holes and gravel to test the work with. What I noticed is that I enjoyed the sound of the motor and stereo a lot more and it did seem to be more quiet. I could spend another $50-75 and 3-6 hrs installing more material in the doors and firewall etc... But, at this point I do not really see the need. I think I made a marked improvement over what the factory has done and at this point I do not think I need to do any more. Time will tell.

It only takes about 5-10 minutes to get all the rear panels and spare tire out of there so don't be afraid to tackle this one if you have modest skills. I can't seem to find the finished product pictures. But, here are the ones I took with all the panels out:

http://i7.photobucket.com/albums/y25...Z/IMG_3509.jpg

I'd second that.... Plus, one of the members said it might help to put some FatMat /DynaMat material on the backsides of the fender well liner. Not sure exactly what that means. However, there is a plastic liner that is inside there that I'm going to have a look at. I think putting a bit of material behind that inner fender liner might help.

That plastic liner is where I put Dynamat on mine for the front. It helped a decent bit with noise. Just be careful not to cover up the mounting holes as I accidentally did. I just poked through and all was fine though.

Frost King
 

I thought I was the first to use Frost King. Ive never seen anyone else mention it previously. Well time will tell.

Maybe it they cleaned the streets where you guys live this would not happen!:icon18::happydance:

Agree..They should just take a piece and put in in a 120 degree oven for a while and see what happens before doing something that might ruin the car just for the sake of $100 dollars..

Actually, they do they do, all the time. Roads are very clean here on Southwest Ohio. It's not like Michigan, where the Mafia controls the road crews and they still have tons of dirt roads.

I just think it's everyone's different perspective on the noises they find irritating. A lot of folks here hate the tire noise. To that I'll use the over used phrase, "it's a sports car, and tire noise is good." I like that it's got a lot of tire noise. Makes me feel like I'm in a beast! :tup: This tire noise is "in" everyone's Z, but it only bothers some.

The pebble noise is there too, in each and every Z. Everyone has it. Some have said that while they hear the plinking rocks, it doesn't bother them a bit. Others have said they've never noticed it, which just means it REALLY doesn't bother them (or every car they've ever owned has also been a tin can so they expect it to sound this way). And others like me don't like it. We want a sports car with engine and exhaust and tire noise, but we don't want incessant plinking just over my shoulder.

So it's just all about what bothers the individual in particular. :cool:

Frost King
 

Now. Bonzo, I re-read the thread and found one post who mentioned he had a buddy use a homeowners product on his RX8. Had a problem with smell and melting. He didnt say it was Frost King. Frost King is meant to insulate and dampen vibrations on metalized ductwork that transfers heat to your home's rooms. Wasnt trying to be cheap. After seeing Dynamat , Frost King is thicker, so I chose it instead. Money wasnt a factor. Shyt, Id spend anything to satisfy myself with my car . I will monitor the product and let Evil and others know who may use it. By the way, My wheels and tires are on the way and should have them on late next week. Thats why I did this. The base 18s are said to be quieter than the larger 19s. My tires will be 255/295s Hankooks V12s. Ill report back on the issue of noise after the install.

I find it hard to believe Frost king would fail like that since its primarily associated with High temp heat ducts. Not worried at this point.

Evil
 

Me either

So far after my install the pebbles aren't bothering me. I went on a nice long easy ride yesterday with the wife and it was very comfortable in auto mode. I do still hear tire roar over the different surfaces but, it doesn't seem to be as bad as it was before and more like what I'd expect out of a sports car. I do have Pilot Super Sports installed and a mild exhaust that covers up some of sounds that were bothering me before. I did notice that the exhaust sounds better inside the car and that there is less droning. Which is a big plus. It's just very mellow rumble tone from the exhaust now. Just the way I like it. ;-) It's a lot like my Firebird now with just a little performance tire roar and rumble from the exhaust. You can still talk over it normally but, when you get on it they're like banshees screaming to get out. Nice balance....

I still can't believe how quiet my Vette is in comparison. I imagine there is a bunch of sound deading material in that Vette.

Mecinoid, do you feel the rubberized undercoating in the wheel wells helped out with the pebble sounds? I have dynamatted the whole hatch and lined the rear plastic fender liners with dynamatt. I still get the pebble sound though, i would say i reduced it by 20%. Road noise overall is down about 50% though. I tapped on the metal part of the wheel wells and even where i dynamtted they still still ring/vibrate like crazy. Almost like there is a cavity between the exterior wheel well and the wheel well in the hatch.

Results
 

I drove for an hour Sunday and I was simply satisfied with what I did. I used a product bought at Lowes called Frost King and lined my hatch area with 2 layers. Removed the spare and added 1/2 inch of carpet insulation over the insulating product. Everywhere I could add I did. I believe its necessary for more than Dynomat or other products. Think about it. If you could see what insulates a sedan that has no issue. I bet its not Dynomat. too costly for auto makers. Probably just some foam or cloth like products along with rear seating materials. So i left out the spare and folded a small bed comforter and now use the hatch area under the coroplast(the plastic just under the carpeting piece) as an unseen storage compartment. Im done. Im happy. Its a sports car.

I'm in with you. Feel the same. And yes, I think there is a cavity as you describe.