If you ever changed a heater core in a car then you should understand it is a pretty simple system consisting of a blower fan blowing over a small radiator coil and enclosed inside a box.
I'm waiting for one of our fabrication gurus to yank a small heater system from a junk car and retrofit it to a Ranger.
I think where this becomes way more complicated is if you try to add the controls for redirecting the warm air flow between defrost, panel or feet.
My thought is you could get such a simple system out of something like a Yugo or tiny sub compact car for next to nothing and have some real fun getting it all plumbed and electrified to do the job.
You guys down in the southern end would need nothing fancy while up here I might want to find a unit out of Greyhound bus for when the temps go below the zero mark.
I have also contemplated one of those add on deals from the rear of a van that appear to be pretty much self contained as long as it works off the coolant system rather then fully electric.
This would be a great project for a few of us to mess around with and I really see no good reason why the Polaris one should be so rediculously expensive. I wonder how many perfectly good units got crushed today at my local auto graveyard?
Gary