If you haven't checked the page on my car yet, then I'll just say my car isn't exactly the quietest thing out there. Intake, header, exhaust, motor mounts, and coilovers definitely take their toll on a quiet ride, but no matter, that's what deadening is for. I started off with a 100sqft roll of Fatmat Extreme and was very unhappy with it, it seemed to go on fine at first (other than the smell), but a couple months later it started falling off. I don't recommend Fatmat to anyone out there, sure it's cheap, but if it doesn't stick then it's really not doing its job. Go with something else instead, you'll be much happier with the results.
Here's the trunk all stripped down to nothing
And then with the fatmat in place. I don't have any pictures of the install process, but at the rate that my fingers were bleeding I figured it would be best to leave the camera alone until I could clean off, which happened to be after I finished. As a side note to anyone out there planning on deadening their car, GET A ROLLER! Your fingers will thank you when you're done, that I promise you, and make sure it's not one of those crappy plastic ones, they'll just break within 30 minutes or so, you need one of the ones with a wooden roller and a strong handle.
And the trunk lid, what a difference that made, no more rattles
Interior back together and the amps back in
Here are my crappy stock doors, note the gaping holes. Those effectively kill the speaker's baffle and lead to huge amounts of cancellation, especially in the midbass. If you have any kind of respectable system you should deaden them as mine are at the bottom of this page, sealing all of those holes. Believe me when I tell you that the differences are huge. A set of $150 speakers with $50 of deadening on the doors will EASILY outperform a set of $200 speakers with no deadening, this I promise you. Spend some money on a lot of good deadening for the doors and you won't regret it, I would do at least a layer or 2 on the outside skin (the sheet of metal where if you were to drill a hole in it, you would have a hole in the outside of your car), and 2-3 layers on the inside skin (the sheet of metal that the speaker mounts to).
After all 4 doors were done I decided to do the roof to cut back on wind noise. It definitely killed almost all of my wind and rain noise, but a side effect that I wasn't expecting was that it greatly increased my exhaust noise, I guess because it ended up "trapping" the exhaust noise in the car.
After the trunk, trunk lid, floor (which I have no pictures of), roof, rear deck, and all 4 doors, i decided to do the b-pillars to cut back on rattles. It seems to have worked, and what else was I going to do with ~3sqft of deadening?
Several months later I decided that one layer on the outer door skin and one layer on the inner door skin wasn't enough, so I went in with some Second Skin STFU-80 and put 2 extra layers on the inner skin of each of the front doors. This addition made at least as much of a difference over the single layer as the single layer made over nothing at all. It was definitely worth the effort. I'd also like to add that Second Skin deadening is worlds above Fatmat. It uses a butyl based adhesive which has no odor and sticks so much better than the asphault based adhesive in Fatmat.