The back up cameras that you buy, like the ones in the license plates, There just regular cctv/cmos camera's, correct?
So in theory could I take a small bullet cam, or take the board out of a dome camera and use it as back up cam?
At the same time could I hook it into the AV in on my HU and be able to use it any time, not just when I'm in reverse or do I have to hook up the reverse lead to get the AV source to come on. In short is the reverse lead a switched power for the AV in on my HU?

 

Keep in mind that the back up cams which you buy are weather proof. So you don't want to use just any cam. I have a Kenwood backup cam that has night vision and it works great.

 

Can you point us to where you got it and how much it cost?

 

It's the Kenwood CCD-2000 rear view cam. I bought it straight from my installer. You can get it on ebay for about $140 which is a good price. Crutchfield has it for $220.