Rear facing camera's trump my system every time. Picks up the ones on the opposite side of the freeway a long way away but obviously that's of no value. Will pick up the ones just as I am about to pass them.

As for highway patrol cars etc. On the way back to kal mine went off with no car in sight, two minutes later a patrol car passed me going the opposite way. Was quiet impressed with that as visually I couldn't see the car nor did I know it was coming.

Mine consists of beltronics detector hard wired into car with f/r sensors as well.