i just added a propane stove to my car's break down gear.yes i know about fumes,thank you.every winter i tell myself when we get a sub-zero evening i'm going out and sit in the car with using the supply's i have and see how long i last.the plan is to string a rope thru the front of the back windows and hang a old blanket from that to cut down on the space i would need to heat and get into a mummy bag up to my arm pits and put on a old down parka.some heaters to try out would be a candle lamp and single burner propane stove.i can see two types of situations,one a sit and wait for help and second an attempt to free a stuck car which would involve outside work and then back in for warmth and meals.