Ultarc, you could power them with the rear defroster like I did. I hit the defroster button and the back-up camera stays on full time.
http://ecomodder.com/forum/showthrea...tml#post457654
The rear view camera has a limited function out the back (because it's a wide angle lens and anything behind you looks like it's half a mile away), but it's freaking awesome for cars coming up beside me. There's no blind spot behind the Insight of course since it narrows in the rear, but there's a giant blind spot on the sides! As cars come up on my sides, they disappear from the side view mirrors, but my wide angle rear monitor sees them until they're right next to me, so I can see the back of their car in the monitor and the front out my side window!