Because a 12 volt, 100 watt heater will warm your tush (which is already internally heated to around 98 degrees) therefore it stands to reason that it will also defrost your windshield (which is much larger than your tush and only at 30 degrees or so) is quite an assumption . . . . and one which has already been proven false by many of us who actually tried doing itLocker wrote:So the voltage system i same - consequently, it will work!