My wife just had to get a new BMW back in March and in riding in it, I realized just how noisy my Escape is. So I started looking around and talking to lots of people and decided to add sound deadening mat.
Now for those that know me, you'll know I can't do things in small amounts. No, I have to jump in with both feet even I don't know how to swim.
Some stats:
~16 - 20 hours will have been spent by the time I get the interior back in.
~130 square feet of mat have been laid down, and I still have to do the doors

90+ was the average temp on the days I worked on it (no garage, the green you see in the picks is the tarp I stretched over it to cut some of the heat down).
I have some advice to those that are thinking about doing this themselves (especially to this extreme), if you don't absolutely and without any hesitation love your car, pay someone else to do this. It really isn't hard work, just tedious and painful (in a few ways).
Not pictured (but also covered) are the tailgate and the spare tire area.
Looking forward from the rear:
Right rear "trunk" area:
Left rear "trunk" area:
Roof:
-dave