It can be done (but I don't know how), but when you get in, start the car and want to drive straight away - backwards - the camera's response is too slow. It takes a while for the camera to deliver an image. The reversing camera that comes standard in my car is significantly faster.
And if you're driving a sedan, the camera is far from the end and just a rough guide. With a station wagon on the rear window, it's much better.
However, the slow reaction could be due to the fact that my camera is not constantly connected to 12V. Maybe it's faster if the power supply is continuous, i.e. with park mode and hardwire kit. Maybe others can confirm that?