I think my topic title was fine considering that I was asking specifically about the Power Magic pro, other units may differ.
Also snailtrail in that topic there is still no clear answer to the question of adding 2 cams to a unit designed for one, only maybe's. From what I have read on this site and others on the net hardwiring is possible but you should check with the person doing the hardwiring if they can do it before spending your money. Or buy one with 2 inputs.