I purchased a complete sound deadening kit from Sound Deadener Showdown and installed it by myself over the course of a few days. The documentation of my install process can be found here.

I found the process to be laborious, but worth it. The car is much more livable now. The noise was cut down considerably, but the vibration and harshness were cut down even more. I'm very pleased with the results, and would recommend SDS to anyone looking for a complete sound deadening solution.

 

I used 3MThinsulate NVH material. It is hydrophobic and it is sooooo easy to cut and place. Remove it? Just pull it out. It is the stuff auto manufactures use. The threads are half the length of the NVH waves which is why it works so well.