Well, the turn signals are part of the parking lamps and the parking lamps are on when the headlights are on. So, I guess you'd have to isolate them somehow. I haven't heard of anybody doing that yet.
That's illegal here for the turn signals to be off but don't know the laws concerning this over there. I mean, they would be completely off and also wouldn't flash.
Maybe you can wire them to a switch? Like the way the AEs could be wired to a switch.