Im in the process of doing the same thing. There really arent many spots to do it on our cars..
Behind the license plate, if you pull that plactic piece off (4 bolts) you will see an area on the left of the plate to do it. Pretty much opposite the keyhole. That is where im gonna mount mine when i get a chance.
Let me know what you end up doing, and post some pics when u do it..
flaming river has one like i was talking about on summit for ~80
the only thing i dont like about the setups where people actually use it on the decklid is all the extra wiring. thats an extra several feet you DO NOT need. the way i want to do it keeps that to a minimum