A good quality fully automatic car aerial that is designed to fit negative earth cars and is electrically operated and powered by the car battery. The aerial will only extend when the radio/cassette is switched on and is retracted when the radio/cassette is off, so greatly reducing the risk of the aerial being damaged by vandals. Power and control connections to the aerial are made by three wires: green and red, which have bullet type connectors, and a black wire which has an eyelet less…