I'm having a brain fart: some years back, I saw little gizmos you would plug into your lighter to maintain clock & radio settings when disconnecting your battery......the kind I'm thinking-of ran on a couple flashlight batteries - just enough so you didn't lose settings. What were they called? Are they available for cheap somewhere? I've visited a couple battery shops here and they never heard of such a thing.......and besides the clock & radio, the windows, seats tranny and who knows what else will lose memory if power is completely lost. Thanks !!