If I buy android head unit plug and play, can you build in road cam?

most of the android units have more than one camera in. Would it be easy, or is it obvious that you could do this and I am not reading it in the features.

I have read through the forums and I cant seem to find an answer to this question. We are becoming a 2 prius household and the new 2011 we are getting has no back up camera, or nav, or bluetooth. It looks like If i buy a unit that is made for prius without premium sound, it comes with all the connections, to plug and play the radio with me having to run a wire for the camera and navigation.

I almost feel like i am being too greedy to think that i could plug in a front facing camera and have it all in one unit.
I cant link it but here is the title of the amazon ad
XTRONS 8 Inch HD Digital Touch Screen Car Stereo Radio in-Dash DVD Player with GPS Dual Channel CANbus Screen Mirroring Function for Toyota Prius 2009-2013
. Clearly I am on a budget as we are buying used cars v new ones. Any suggestions on better units would be welcome as well