Yeah-no worries mate. I'll write out the details about the solenoids in the next couple of days. (very simple-I suspect you'll be able to set it up in an hour or so considering you're an auto sparky)
If you can get hold of a supra or cressida manual though it will be even easier to explain. I'll start jotting it down and try and get it up in the next couple of days.
It can either be done with relays or with transistors-depending on your preference. A transistor set-up will be more compact, but the relays are easier