thought i share my experience with this product.

on my previous car, i bought a two rolls of dynamat... about 150-200 lbs worth. did the whole interior. it worked very well, but just added too much weight.

so on my new s2k, i orginally didnt want to add extra weight to this car, but after installing a 10 inch sub, amp, speakers.... i just cannot stand the rattles. i spoke with a few car shops, and they recommended professional grade undercoat spray.

i bought a few cans from my local autozone, it was on sale at 2 for 10 bucks.

works extremely well. at least 70% of the rattles are gone. and i have less road noise.

i would say for the price and weight savings... its works about 75% of dynamat.

i would highly recommend it.

try doing some searches on yahoo... undercoat spray and audio. you'll get some hits with reviews.

i was going to try the expanding foam from home depot. but that only works well for the trunk area.

for 5 bucks each... at 17oz a can... you cant go wrong...

 

I thought about the expanding foam as well, was worried about it expanding and causing problems especially if used in the trunk lid.

 

theres three types of expanding foam that you can buy. get the middle one. that way it wont bowl the support beams or trunk lid.

 

Double expanding instead of triple?

 

there are three different types that i know of and use.

1 is for window sills and used to fill small gaps.... when it drys... its soft. kind of like playdoh/rubber?

2nd type is where it expands... about 5 to 10 times its orig. mass.

3 type is where it expands.... 10-20 times....

the 2nd and 3rd one gets very hard once it dries... pain in the ass to scrap off.

 

Where did you use the undercoat spray? inside or out? any pics??

 

I use 3M undercoat spray or the Duplicolor undercoat spary on my sub boxes. They both work very well.

 

can you put this stuff in the exhaust channel under the car in order to stop some of the heat transfer and noise? or will this stuff melt or burn?

 

very tempting. where exactly did you spray all the sound deadener? I also dynamatted my previous car, but won't do it to the S because it weighs too much.