I carry a 5 lb Kidde ABC fire extinguisher in my bus at all times. 4-5 times I have been the first one at the scene of an accident or car fire and needed one. The smaller 1-2 lb ones fit in more places, but have only put a dent in the fires I have been at. And the one I have is rechargeable, not a one use throwaway, and also complies with DOT regs for fleet vehicles. BTW, I also have a first aid kit and a tow chain that I keep in the van.
Les