I once had an engine fire in a 1980's Ford Pinto, on a highway offramp (I-95 in Boca Raton, FL) it must have been 1986. After I opened the hood the flames got bigger (more oxygen). Someone in another car had just a bit of water left in his plastic water bottle and that was enough to put the fire out. I think it cost me $500 to get it all fixed, back then. Since then I always carry a fire extinuisher. But, once, maybe a year, later, I passed a pickup truck parked on the side of a road in West Palm Beach, with two guys frantically working to put out an underhood fire in that truck. I thought, great, I can help them out with my extinguisher but as I stopped to begin to do that, they equally frantically began to gesture me to move on and leave. I then thought, great, they probably just stole the truck by short-circuiting something and I better get out of here! True story.