Progress report!
HDMI switch, USB power, Configured Raspberry Pi and Chromecast are in, up on the center consoles middle toggle switche flips between three HDMI sources.
1) Chromecast
2) Raspberry Pi
3) MHL connector (Glovebox)
Down on center toggle switch turns the USB power module on and off (Turning off all devices).
Waiting on some cables and extras to implement canbus related stuff but for the time being I'm now able to use chromecast, MHL and play any game on 30+ game systems using a wireless Xbox 360 pad I store in the glovebox.
Pics:
Will take some better pictures tomorrow when it's light.