Ok, this is perhaps where my lack of electronics will become apparent, but I thought that there was no internal difference between 110v and a 220v ceramic heater; this would be because it doesn't care how much voltage is going to it since the resistance varies based on the amount of heat produced rather than voltage. This would explain why, in contrast, coil type heaters have resistors in line, whereas ceramic do not. If however, there is a difference between a 110v and 220v ceramic heater, couldn't you compensate by using two in parallel 220v elements to be the equivalent of a 110v heater? Ok, I'm going to shut up now because people will start worrying for my life that I know so little and trust my life to an electrically powered car.....