I'm currently in the process of insulating my car as well. I've come up with some tips, I'll list them at the bottom.
The Jute padding on the carpet I bought is in the spots where feet will be. It may help insulate, but I believe in terms of the carpet it's main job is to be floor padding, which is Jute padding's same job when installed in a house floor.
Also a good thread on the sound deadener subject:
http://www.78ta.com/HTAF/index.php?topic=36815.15Just a quick outline of what I said in that thread, I purchased a sample of FatMat and a sample of ThermoTec (sold at the speed jobs like Summit Racing, Jegs and cheapest I found it was Amazon). FatMat is stinks a lot more than ThermoTec. ThermoTec is a dead ringer for Dynamat but at half the cost. I believe FatMat is a mixture of materials including asphalt. If you go the FatMat route, be careful where you use it. Anywhere that may reactivate/melt the FatMat you may re-introduce the stinky smell. Butyl rubber will also have a smell, but it's much more palatable and is what the factory used for some spots as well.
Just keep in mind what your goals are. If you are trying to insulate and minimize sounds from outside, the EZ Cool / closed cell foam aluminum backed insulation is the cheapest and best way to do it. If you want to deaden sound and insulate, sound deadener like FatMat/ThermoTec/Dynamat is the best way to do it. If you want to achieve both, you need both products.
Remember that sound deadening and lowering sound levels are two different things, if you want to achieve both you need to address both with different products. Like the walls in the office I sit in now the walls lower the sound levels of the offices next door but I can still hear deep voices, books dropped, and door slams. This is because the walls have no sound deadening in them. So the wall and insulation may lower the volume of sound from the offices next door, they are not killing the deep base sounds. Radio studios use heavy rubber mats against the walls to deaden those sounds, butyl rubber and asphalt can achieve the same for our cars.
The aluminum spaced from the surface is what is achieving the insulation. Both sound deadeners and the closed cell foam with aluminum achieve this, though the closed cell foam will insulate better since there are 2 rows of aluminum and it's spaced apart further than the sound deander.
I'm personally doing a multiple product approach. Originally my plan was to cover 30-35% of each metal panel with ThermoTec deadener, followed by foll coverage of Closed Cell Foam Aluminum Double sided material TAZ is using. I purchased mine from
http://www.lobucrod.com/ called EZ Cool, came with a roll of aluminum tape to tape the seams with as well. It's cheaper to buy at Home Depot/Lowes/Menards though.
But plans and execution are two different things and my plans have changed now that I'm actually started installing the deander and insulation.
I am now putting sound deadner 100% coverage along the firewall and rear deck lid. Beyond that I am installing deadener at about 70-85% coverage over the floor pans, center hump, and 100% over the rear wheel wells. I'm then installing deadener anywhere I have gaps/cracks I want covered. Then I am taking the closed cell foam aluminum backing material and covering those panels where I did not install deadener 100%, as well as full coverage across the bottom floors and the rear back seat. Essentially, deadener in high heat areas (firewall), speaker vibration areas, and any flat/large panels, and closed cell foam in flat areas where deadener is not covering the area 100%. All gaps of aluminum deadener or closed cell foam are taped with aluminum tape.
My tipsCut deadener into rectangles/strips: At first I was cutting patterns out of the ThermoTec deadener to cover areas such as the firewall. I quickly learned this is a very hard way to go about it. I eventually found that you're better off cutting the deadener into strips and various square/rectangular sizes then like a puzzle apply each strip in spots where it covers the panel best.
Closed Cell Foam Tips: It does not bend as easily as the deadener, so plan on using it across flat spots or outside curves. I cut my sections of closed cell foam to fit over a section and then use aluminum tape to tape it to the deadener I already put down. If you do not have deadener to tape the closed cell foam to, you will need to use a 3m adhesive to glue the closed cell foam to your floor body with. I'm avoiding glue as much as possible hence the additional deadener coverage than I originally didn't plan for.
You can cut deadener with an utility knife, it will dull the blade quickly though. Straight cuts are easier, circles and shapes are harder to do.
Closed Cell Foam can easily be cut with scissors. Closed Cell Foam between the door panels and the door is perfect for this application since it will not get damaged if it was to get wet.
You want to cut your aluminum tape with scissors. Ripping it like normal tape makes it really hard to peal it later on.
Here's a picture from last week when I first started. I'll get some more pictures when I'm done with the deadener and about to install the closed cell foam.
