Well this afternoon I finally got Xan (The CarPC's name...) up and running.
My WhiteBream power supply would not boot my MII 10000 EPIA, but oddly it does boot my CL 10000 - which is a bit of a mixed blessing. Whilst I loose the PCMCIA slot, I have gained another USB controller / NIC
GPS works, if a little buggy. (Coming up to a major roundabout, wanted me to go straight on, until I was actually on it then it blurted 'Take third exit). The GPS system and Navigator 4 was very accurate though (down to 10m I'd say at 50mph).
Still a lot of work to do, but at least I have something to show for it now