Price: £299 (plus £4.99 p&p) Sensors/alert: Camera/monitor

Comprising an AVCAM-9 camera and AV35DM 3.5-inch colour monitor, plus connections for two more video inputs, this set-up is permanently wired in. But the camera feed has to run the length of the vehicle and the lens, attached to a threaded rod, might be tricky to fit in some cars. Great quality and a clear image – pity about the price.