That would be handy.
There is a permenant live that goes to the dome lights, so you could tap into there. Be carful with the wires, as the dome lights have a permenant live, permenant ground (switched on by you when you press the dome light) and a selective ground which is activated when you open the door. Its not a selective live, prememant live and permenant ground as I thought it would be. So read the service manual before tapping into the dome light wires