I have a Zodi Outback Combo X unit that is a propane heated shower, cookstove and tent heater in one unit. http://www.zodi.com Now that the weather is warming up and I'll have about six months before I'll even consider using the tent heater I am thinking on a larger scale. Has anyone considered developing a propane or gas heater for heating the inside of a truck while the engine is off for car/truck/cruiser camping in butt-ass-cold weather? I've slept in my 80 in temps as low as 5 below zero but it is not the most pleasant thing to get out of the sleeping bag in the morning with no heat . I was thinking along the lines of the Zodi tent heater with a coiled tube above a burner and a fan to blow the heat through duct work but somehow integrating the duct or actual heating unit so that you can manually open an air duct and have warm air from the aux. heater blow through the in dash heating vents (ramble). This may require the fabrication of an all new unit somehow integrated into a bumper or other 'safe space' on the truck and running duct work to the inside of the truck or simply tapping into the existng heater core. Thoughts ?? Another thought that may or may not work is to design a propane powered block heater. I am not that familiar with these systems but it would seem as though a warm block would provide for a warm heater and the only power draw would then be on the fan to blow the heat. It would be nice to be able to operate and turn on/off the gas and adjust the temp and fan power from inside the truck. Also the DC power draw should be minimized so that it only powers a small low amperage fan if anything. This is just a brain storming session that I wanted to take online and bounce around. Thoughts ??? Ideas ???