I decided to add sound deadening insulation to my ILX to help reduce the road and wind noise while driving. I've had the car for about two years, and as many other posts and reviews have mentioned, it is not the most quiet vehicle I've been in. While I don't think its as bad as some very negative reviews I've read, I decided that since I'm planning on keeping this car for many years, it would be worth the time and effort to invest in some sound proofing (plus I have plenty of free time right now!).

After doing a fair amount of research I decided to install butyl rubber matting covered by closed cell sound deadening foam on the interior of the doors, floor and trunk. So far I've completed the doors and trunk and am assessing if I still want to do the floor or not (the improvement is already rather impressive).

Materials:

Butyl Sound Deadener:

Closed Cell Foam:

Weather Strip:

Misc:

Process:
I started with the driver door, by removing the interior panel. (Note: I would recommend starting with a different door, as you are likely to get more efficient and learn as you go, so you'll do a better job on the driver side door if its the second or third door you complete. Just a tip I wish I had done). The door panel is held on by three screws and several clips that pop out. There are two screws behind the door pull latch and one screw under the rubber matting in the pull handle /grip. After removing the screws you can run a tool (I bought the listed trim removal kit that helped a lot to avoid damaging any panels, scratching the car or breaking clips) or your hand around the sides and bottom of the panel until all the clips unhook. Pull the panel up to disconnect it from the door shell and unhook the wires connected to the power windows/locks and pull latch. You can then set the interior door panel to the side (somewhere it will be safe and protected).



Interior of rear passenger door. This is the factory installed "sound proofing" consisting fo a thin piece of black foam glued to a thin piece of white plastic.

I then cut out the factor installed "sound proofing", keeping the black foam insert, but discarding the white plastic. I also pull the white caulk off of the door frame to ensure proper adhesion of the butyl. (I found that if you pull firmly, but slowly the caulk will release rather cleanly almost in one long strip). That exposed the interior of the door, where I then installed the butyl and foam to the interior of the exterior door shell.


Front Driver Side Door. Installed butyl along the interior side of the exterior door shell.


Front Passager Side Door. I started installing the foam over the butyl, including behind the speaker.


Once I covered as much of the interior as I could, I then covered the interior of the door for another layer of sound proofing. Make sure not to cover any wires or lose any of the connections!


Front Passager Side Door. Covered interior openings with Dynamat.

After that is complete you just have to reconnect and reassemble the door panel. This process is the exact same for all four doors.

I also decided to put another layer of weatherstripping around each door, as I saw this suggested in another post online. I decided to do one continuous strip around the entire door that goes between the two existing layers.








I didn't take any photos of the trunk, but it was much easier than the doors! There are three carpeted panels in the trunk that slide right out once the plastic clips are removed (they all pop right out with a flat head screw driver or similar tool). I installed the butyl matting in as many flat smooth area as I could find (mostly in smaller strips than I used in the doors). I also used the spray sound deadener listed in the spare tire well, and other tight areas within the trunk. I then let that dry, installed the foam over the butyl, focusing on covering the wheel wells, back of the rear seat and the under side of the speaker deck.



Trunk interior. Underside of rear speaker deck.

Overall I am very pleased with the results! I've noticed a huge reduction in road noise and wind when driving. The stock sound system (Premium version) also sounds so much better already! The speakers are louder (at the same volume as before), clearer and brighter. I have not disconnected the active noise cancellation yet as I've seen suggested and might try that to see what the difference is. I still have a good bit of materials left over, so I'm thinking about doing either the firewall (under the dash) or roof of the car, but I'm not sure if I want to get that involved and take apart those things. I think I'll drive it like this for a little while and assess before I do any more sound proofing. I am planning on upgrading the speakers/amp? and will be doing a different post to discuss that and get some advice.