I bought a project e53 about a year ago (overheated). It had a tired, cheap android head unit and a cheap non-functioning rear camera. I replaced both head unit (with an Xtrons Android) and replaced the rear camera from amazon. ...both work well. Camera is mounted in a hole drilled in the trim piece in the hatch that holds the license plate light. It needed to be angled a little bit, but not a bad location.