Here are some new pics I took when I needed to pull it all apart again. I found that the Mini was just getting too hot this summer due to the lack of circulation, so I added some fans to help move the air about.
Here is what all my wiring looks like:
At the top is my external sound card (M-Audio Sonica Theater).
The long blue thing between it and the P1900 is a POS USB hub that I have since removed.
Here is the base to my center console in place. I have since cut a giant hole (pretty much extended the hole for the handbrake all the way across) so I don't have to keep ripping everything apart to make tweaks:
Here is the cubby in the center console where I keep the Mini. You can see the CPU fans I used:
Initially I had them running off USB power so that they wouldn't be so loud. I found that A) they didn't move enough air and B) they were only on when the system was on so didn't help that much.
I have since connected them to a 12v always on source (with a switch) and I leave them on all day. This has taken care of the heat issues (the Mini's fan barely runs now). At some point I want to make them solar power and hook them up to temp sensors so they only run when they needed, but this is good enough for now.
Here is the Mini in the cubby with my hub:
I have a couple more, but apparently the camera decided to use raw format instead of JPG so I need to convert them first.