San Diego does not get very cold but I have had a day or two when I had to defog the windshield. So...
I am installing a ceramic heater with defrost vents and an interior vent.
The heater box is homemade using aluminum sheet metal, a 12V fan and the original plastic housing for the ceramic element from my $25 space heater. I purchased a defroster kit from Mill Supply for my defroster vents and heater tubing and flanges.
