Had a bit of spare this morning so thought I'd have a go at this. So I got the wiring diagram out, to see if I agreed with the wiring before I blew any fuses. I didn't think it needed the plug removing from the dim-dip unit so left it alone, then set out modifying the G6 plug thingy. Now my car is a 1988 Turbo S and this appears to work on my car and I just thought I'd share, please don't blame me if you try it and it doesn't work on your car.
So I ground the link away between the pin/spade 0 and numbers 2 and 9, then I soldered a wire to the back of the back of the 0 pin/spade.
I had to twist the spade connector to fit inbetween the other connectors and bend it over so it fit under the board. I cut the corner of the board and all the bits of plastic out of the cap.
so when I put it all together it looked like this from underneath
Then I plugged the connector into the number 3 socket not the number 4 as the other instructions say.
When I tested the number 4 socket on my car it had a small voltage when the sidelights were on but number 3 was only live when the headlights were on so I used that.
And this is what it looks like all pluged in and finished
So now the headlights only pop up with the ignition on and the headlights on, and go down again when I turn the lights off completely. The side lights still come on in the headlight unit when they are down but cutting the spade connector off the light bulb solved that.