Simon, I was the one who put the wiring instructions together that were posted here...They were initially posted on ClubGP and OQCGP.com...
You can make the HUD and DIC come on by using a switched 12v power source to the DIC at pin B9 (ign 1 voltage) and at the HUD at the switch on pin A (acc power). Your DIC will come on when you put the car in ACC if you don't also put a switch on pin A2 if that matters for your case. I would just use an "add-a-circuit" and run power off the fuse block to a switch mounted somewhere. Don't switch the constant Batt + wire for the DIC (A1) or you will lose all data every time you turn off the switch.
