Glancing at the thread title, my first question was going to be, "What country are you planning to attack, first?"
If you wanna get all hardcore about shakes n' rattles, you've got a LOT of work ahead of you with a Fox. I think squeaks and stuff were DESIGNED to be a part of these cars. You'll have to strip everything in the interior down to the bare metal, hose it with some major sound deadener, lay some Dynamat-type material down over that, then some thick-arsed carpet, then spend the next five to ten years putting wedges and padding and stuff between the joints of every little plastic panel in the car. And then you'll still wind up with that one mysterious but obnoxious little buzz or rattle or something that you can never quite pinpoint, and it can somehow still be heard over 100+ decibels of noise.
Seriously, though, aside from totally redoing the interior, you'll just have to push, knock, pull, wiggle, and shake stuff throughout the interior by hand to trace down all the major noises and then use all sorts of little things as wedges/shims to silence them.
I have bits of cardboard, paper, plastic, blue shop towels, rubber, and whatever else scattered throughout the inside of my notch to get rid of the really annoying sounds, and I still have a few I'll never quite eliminate. I mean, sure, I scraped out the stock sound insulating material, but road and exhaust noise is different than some stupid plastic interior piece making an "EEE-EE-EE-EEEE-EE-EEE!!!" noise from every little vibration when you're doing 75 MPH down the Loop 202, y'know? I also have to leave my windows up about 2" on both sides to keep them from rattling when they're rolled down because the dew wipes are rotted/disintegrated.
So ... improvised shims and wedges are the cheapest and simplest way to go for a lot of stuff. After that, again, it's a matter of how much you want to strip the car down and line the interior, and how much time/expense you're willing to pour into that project. It's a Fox, not an SN95 or an S197, so don't expect the acoustics of a bank vault.
