I have been looking at the other shower threads, mainly about making my own heater exchange. It is very workable to run an exchange off of the engine coolant and pump the hot water out to the shower.
An idea that I had is if you are camping on a trail you probably have a fire going anyway, why not use some coals of that fire to heat up the exchange instead? Or use some charcoal briquets around the coiled copper? You wouldn't want to get the little coals burning too hot, but I would think that would be hot enought to heat the water without having to jump into the car to turn it on and connecting some hoses.......
just some thoughts.......
An idea that I had is if you are camping on a trail you probably have a fire going anyway, why not use some coals of that fire to heat up the exchange instead? Or use some charcoal briquets around the coiled copper? You wouldn't want to get the little coals burning too hot, but I would think that would be hot enought to heat the water without having to jump into the car to turn it on and connecting some hoses.......
just some thoughts.......