In my younger/cheaper days, I used to scavenge firewood after the crowds would leave the camping area at the end of the weekend. Generally, this meant grabbing piles of unused firewood from near the fire rings of vacant campsites. Every once in a while I would come across a prime log (think 2 ft diameter x 4 ft long unsplit hardwood) that was still smoldering in the fire ring. As this was in the desert where water was scarce, dousing the logs was not really an option. On more than one occasion, I was able to simply kick the log out of the bed of my pickup into the fire ring and with a couple of lung fulls of air get a raging fire going.
While I doubt one can truly safely transport a smoldering log, what is the best way to do so. For example, putting it in the trunk of a car would minimize airflow, but be really dangerous if it ignited.