Is it possible to connect a backup camera to the MFD???

Is this even possible? I know that there is an adapter that I can buy that plugs right in to the nav unit, but I don't want to spend $200. My Prius has a slot to the left of the license plate for where the camera should go, so I do believe that it was an option. I was trying to read up on this, and from what I came across, I believe that there is a harness of some kind running to the back hatch that I can connect a camera to?? I really want a backup camera, but don't want to have an external monitor on my dash or install a new head unit with a camera input.

Any help would be much appreciated! I don't really understand wiring, so any and all clarification will be much appreciated!

Oh, and I have an '05 Option 5 Prius.

Thank you! And if this is in the wrong section, feel free to move it or whatever you guys do