Does anyone use a cigarette charger device to charge their ipod in the car? I recently bought the Monster Cable icar charger which plugs into a cigarette lighter socket and also has a line out output that I then plug into my aux input connector. The setup seems to work great but I am concerned that if I leave the ipod in the car connected to the charger that eventually it will drain my car battery since the cigarette lighter socket seems never to shut down. I hope this makes sense. Anyone know for sure?