I have an old infrared reversing camera and monitor which I use for seeing up under the dash of cars if doing work on them.
Makes the job very much easier as the camera lights it up like daylight, and I don't have to get these old bones into places that I have trouble extracting them from.
I reckon what you need is remote control of the camera - imagine angle parking (without van) and when you reverse out being to swivel the camera to see oncoming traffic. I've thought of making a simple solenoid operated device for that.