I have one too. It's integrated in the License plate frame - so it sits just below the trunk opener - really inconspicuous. The picture automatically shows up on my headunit when I shift to reverse. The cam is wired to the backuplight and the cable for the picture runs from the trunk to the front on the passenger side.
It has nearly a 180° field of view, IR-View and to me it makes backing the car up a lot safer and easier.