UPDATE - 10/17/02 - I'm midway through a total rebuild...same equipment, just a different install...more pics will follow, but here's a preliminary one:

Here's the install that I have just completed in my brother's 2001 BMW 330Ci.
I'm pretty proud to say that it's 100% DIY. All the work was done in my tiny garage. Please be kind and leave me some constructive criticism!
The finished pics will be up soon...
Here's a shot of my brother picking up his new baby.

To check out some specs, head over to http://www.bmwusa.com
My brother decided that he liked the sound and quality of a/d/s/ equipment, so here's what we picked out:
Front Stage: 346is components 
Rear Fill: 336im co-ax 
Sub: 312RS.2 
Front/Rear Amp: P650
Sub Amp: PQ40.2 
For specs, try http://www.adst.com/pages/ads_home.html