Do I live 800 meters high so much snow?? Workplace 950 meters high even more snow! So I have a heater! Question what does it need for petrol !! Set to one hour? at 17 degrees interior ? I have no mirrors heating and rear window heating ! But steering wheel heating and seat heating! How do I get the rear window free? Outdoor mirrors are also not free! Pretty Mies at the new price of a Phaeton ́s ! gruss Michi