b5 install (and a question on reversing camera location)

[fellow dubber]

hi all,
managed to get around to starting my install today, armed with a few tools i set to taking my old one out. it had a factory gamma unit in there, soon figured out how it came out, just made two bits of thin steel for the keys, shoved them in and it popped right out!!
a kenwoo0d 627 dvd sits there now and i have mounted the control box to the back seat in the boot along with a vibe 600w mono block to power a vibe 10" sub, and a jenson 600w for the vibe se60 series components in the front and rear doors. not fitted the components just yet because i cant think where to put the crossovers, there is 4 in total. any ideas?

my next mission is to fit a reversing camera, where would you guys mount that? i thought about removing the boot key lock and mounting it in threre, is it as straight forward as it sounds?
my next thought is to mount it in the rear valance, would mean drilling a hole in it and making a mount for it to sit level.
how would you do it? any thoughts will be appreciated

marty.