I was thinking of using a small project box as a "base." I'd leave the wires from the PCM plug they way they are, but wrap them in that plastic loom stuff and run it into the box. I'd then mount the OBD2 port and the switch to the box. Super clean. Probably do something like this for power:
http://www.amazon.com/gp/product/B00...A29H9ZXM6Z907A
Mount the adapter inside and drill a hole for the plug to go through so all you would see is the female end of the adapter. Also, the plug would be removable.
Just thinking out loud...
