I saw a neat way to get around 4ontheFloor's problem. The guy had an electric antenna. He had an internal regulated alternator and didn't need the generator regulator so he gutted it and put a push button switch in it. I forget what kind of mechanism did it but when the hood closed it closed the switch so the antenna could operate normally. With the hood open so was the switch, breaking the circuit. If he turned on the ignition without remembering to turn off the radio, no damage done.
