[SOLVED] Please recommend a tie-in point for the headlights

I am soon (Thursday maybe) going to be installing some under-car lighting. I will have them come on when the headlights are on. I need a recommendation on a wire to tap for the headlight on signal. I tapped the ECU's L7 connector wires for the turn signals on the backup camera mod, so I feel confident fiddling with these wires. Is there a headlight signal in that group of wires as well?

If not, where would you recommend tapping the headlight signal? I *can* tap it outside at the light if necessary, but I would feel better tapping it inside the car if possible.

 

Awesome, dude. You hit the nail on the head. Thanks ever so much.

EDIT: As for why I started a new thread, it seemed to be a different question, so therefore a new answer.