I've never heard of photo-radar photographing the front of a vehicle. I've only ever seen it photo cars from behind after they have passed the device. That way it doesn't matter if it has a front plate or not. Also, the authorities don't care who is actually driving; the tickets are issued to the registered owner of the vehicle, and that's who's responsible for paying the fine. Which also happens to be the reason why photo radar tickets don't go against your record, i.e. they can't necessarily prove who was behind the wheel.