Works horribly when the weather is truly cold. In a Colorado winter, the warmest I could heat up the truck was to about 40 degrees. And the defrost doesn't seem to really do much effective defrosting. I had to rely on anti-fog wipes in the winter.
I would personally use an aftermarket heater. And I probably will. I haven't had much luck with the OEM heaters working that well. I might consider giving up my old one if I do, but I have to stop short of actually offering it for free, or I'll get in trouble for..."advertising".
