Doing a quick search, it appears I might be the first one to finish a install into an mx-3. WOOHOO!!!
Here is a brief rundown of what I have installed...
Dell 2.2ghz micro-atx computer
Dynamix 8" touchscreen lcd
Cadence m3000 component amplfier
Cadence CWM6 component speakers
Orion xtr 2150 sub amp
Phoenix Gold x10d4 subwoofer
Samsung black for 3G internet
and lots of custom fabrication along the way

Now on to the pictures
Here are a couple blurry shots of the screen in action


Here is a rear shot looking into the car

This is the computer stuffed under the passenger seat for now

This is the component speaker in the door with the grill off

and the tweeter...

Here is the component amplifier under the driver seat

Now the sub amplifier (not yet mounted)

Sub in crappy box (Fiberglass mold into the corner almost complete)

And finally the blackjack for mobile internet
