I have the Honda heater, and it was originally hooked up the "wrong" way. They're looking after that now, but even being hooked up wrong, the heater really put out once the thermostat opened up. I have the full windshield that opens at the bottom - I leave it cracked open a bit, and don't have fogging issues. I've got the soft doors and partition; maybe the hard cab doesn't get as much air flow. I was thinking that if fogging became a problem, I'd get one of those little 12v fans and blow it on the windows. It used to work great in the old farm trucks...