Started work on this again. Gathering parts for the computer itself, as well as fixing the fascia to get it perfect this time. Also got the software I need.
Software:
Windows 7 (I'll strip it down to the essentials once it's all running)
Centrafuse Auto 4 with maps as a front end, music player, navigation etc
BlueSoleil for automatically connecting my iPhone to the computer via bluetooth and managing contacts
Hardware:
Motherboard: AsRock H77M-ITX
CPU: Intel Core i3-2100
RAM Patriot G2 Series DDR3 1600MHz 4GB (will only run 2GB if I can get memory usage down enough)
SSD: OCZ Agility 3 60GB SATA 3
Case: M350 if I can't find somewhere to fit the computer without a case
PSU: M2-ATX, still yet to order this
GPS: Nokia LD 3W (to be upgraded later)
Bluetooth USB adapter
ELM327 OBDII USB cable
Cables: HDMI, lots of USB extension cables, various 3.5mm cables etc...
I'm tempted to run radio through the computer instead of using the headunit as that way whatever is playing will automatically mute when I make or receive a phone call or use voice control. Opposed to me having to reach all the way to the AUX button on the headunit (or press the steering wheel control)

Here's a pic of what the front end will look like, nice big buttons to press and hopefully a very smooth interface with the i3. I've also modified Windows 7 a little to remove most microsoft/windows branding so now the interface has Subaru logos and tbSTi logos/wallpaper


EDIT: Also fitted a reversing camera which automatically switches, need to rewire it a bit as there's a 2-3 second delay before I get picture after changing to reverse. It's very well hidden, you can see it in this photo (just) and that was the angle it was most noticeable from

