Thanks for that Rod. I went hunting and found (as should have been obvious) that the power socket wiring is on the back of the power socket. Sigh...

pps:
I want to pick up that switched circuit and hardwire my GPS.
I've poked around the fuse block and I think that I have identified the wires. The fused wire is purple/yellow, and the supply to that fuse is orange/red. Can someone with a wiring diagram confirm this for me?
Cheers;
Pogo.