It's been a few months since I started plans for putting a PC in my WRX, and since I started, I've been trying to figure out how I wanted to get everything mounted..
The initial thought was to mount everything in the double-din space where the radio is, while trying to find an 8" widescreen LCD (bare panel / kit) with a high enough resolution.
And while it's been done, I've been thinking that maybe that's not the best way to go about it, cramming everything in such a tiny space.
Second thoughts were to leave the radio in place, get one of DigitalWW's in-dash 7" LCD's (http://www.digitalww.com/DWW-7VGT.htm), and put it up on the dash in a WRX gauge pod housing, which goes in place of the clock. The computer would have been relocated to under the seat, or elsewhere..
Pic of the dash with the gauge housing (not mine):
And so, my most recent thoughts were to instead place the LCD flush in the double-din radio area, and to place the computer in the gauge pod housing.
The motherboard, I/O ports, and DVD drive would go up in the gauge housing - it's the size of a single-din radio housing, so there's room.
The power supply, hard drive, etc, would go in the double-din radio space, where there's now ample room behind the LCD.
The gauge housing is mounted securely to the dash with a tray, seen here:
Item listed here, under "Empty Gauge Pack Housing":
I'm thinking that the distance between the housing and the radio interior is small enough that everything would be easily cabled together, without long-distance cable runs to under the seats, etc.