Very, very nice work Dave!! Thanks for sharing.
Been there, done that. Ripped the entire interior out just like that, did some mass loading and added carpet padding. You will be happy with the results. Acutally it's kind of a fun project. You really get to see how cheaply put together a $14,000 car really is!!
As Chulyer mentioned, you might want to seal up the access holes on the doors. I initially left them open and then went back and sealed them up. Let me tell you, the effect was the midbass just shot out into the cabin like a cannon!! Can you say vibrating pant legs.

Final product will look something like this:
http://i96.photobucket.com/albums/l173/barnz008/Installpics14.jpg
Also, a 1 cuft square piece of closed cell foam directly behind the driver will help kill the back wave from bouncing off the door skin and causing cancellation. I used a camping pad from WalMart. Deflex pads can do the trick, but there are cheaper options that do just as good of a job. Here's mine as an example:
http://i96.photobucket.com/albums/l173/barnz008/P1011036.jpg
I would also recommend some type of decoupler between the mid and the baffle and also the baffle and the door itself. Weather stripping works great on the mid and Non-hardening modeling clay or strip caulk works great on the baffle. I think this would be pretty much necessary with a metal to metal connection. If it's already done and the pics don't show it, than nevermind. Non-hardening modeling clay on a HDPE baffle:
http://i96.photobucket.com/albums/l173/barnz008/P1011039.jpg
Again, great work! Hope the tips and pictures help.
Looks like you had some hard little workers at your side too!
