After 5 days in absolute manual described using the unit went in my car up in smoke. And in the "OFF" mode. Only by pulling the plug could I avert greater damage on my car !!! Unfortunately not recommended in my view and a big security risk. If you imagine times before you have a 12 V power outlet that is not only on when the key is inserted (had my second to last car), then it is in the morning before a charred scrap heap!