G`day bobber
I was thinking about the same thing, dont know what model bike you have, but on my F1 750 i was going to take the stock taillight and mount it to the tail piece of the seat.
I was going to rivet an aluminium plate to the tail piece and use the stock tail light mounting bolts to fix it there, the wiring wont be any problems just extend it and run it along the bottom of the seat
I`ll try to get some pics to explain better
cheers mate
troppo