I used some sound deadening material called Brown Bread. It cost less than dynomat and
a review of Brown Bread, Dynomat and a few other products name Brown Bread as the best.
There is some more information on it here.
http://www.b-quiet.com/brownbread.html
I used two 70 sq ft. rolls of this to cover the whole inside of my '90 240sx. I covered the front,
rear, doors, and headliner and just about everything else in the car. I also had some extra to
double up on places like under the seats and in the hatch. Check out the pictures here.
Pictures
After the install I noticed so much of a difference. It was so much quieter than before. I have
an Apex'i N1 and before the deadening I had to almost yell at my passenger to have a conversation,
now I don’t have to.
It is good stuff, I recommend it!
P.S. If you don't want to go through the trouble of taking out your whole interior to install this
stuff, I'm going to be selling my '90 this summer.
