Y not wire it to the trunk light? That way it only lights when you open the trunk. So I would say tap the power, inline fuse and ground it. Someone correct me if I'm wrong as I am no way a technical guru.
man just make your self a 12v power source like from the battery and run it to a toggle switch and from the switch to the leds it might seem like alot of work but at least then there wont be any cuttin into anything that could cause a short or problems like that it would be easy 12v and ground........and the switch that has 3 holes one is for the power and the other is for the lights and the last is the ground you dont really have to hook the ground up on the switch thats usually just for the switch to light up.....
