I'd like to know more about the tire buring bit.

How does one light a tire, 'specially if you are already out of gas? And how do you get heat from it? Sit around it like a campfire, trying to avoid the smoke, light it near an open door and try to heat the inside of the vehicle while somehow avoiding the smoke?

And, if the choppers were already looking for them when the tire burning went on, I wonder why the black smoke was not spotted...