Currently have a single lens camera pointing down towards the tow bar. The monitor is where the rear view mirror used to be. I would like to have a twin lens camera so that I can see the tow bar etc but also see directly backwards so as to see the traffic behind me (not for the purpose of delighting in the chaos caused by my strict adherence to speed limits, despite the fist-shaking of those behind me). I have seen various cameras that have two lenses for this purpose. As the wiring is already in place, is it a simple matter of just swapping cameras? When I select reverse, a view with red and green grid warning lights operates on the inbuilt satnav/radio. Would this be affected by changing the camera?