Well the funniest thing happened on our recent road trip. First time I've had the inverter hooked up to the Mazda5 (usually in my Tundra). For some reason with the inverter off but plugged into the cigarette lighter up front, it most hold a charge and then feed it back into the car. When I shut the car off and pull the key out, the radio is still blaring away, but it stops if I pull the inverter out of the cig lighter or turn it on.... very very strange. I've run this inverter in my Tundra the same way for a long time and it hasn't acted this way. Anybody else have an inverter they could hookup and see if it acts the same way? Mine's a coleman 400watt model. Just had to giggle when I figured out what was causing it, I'll be informing Mazda as well.