A fire extinquisher ! I've stopped twice in as many years to help with a vehicle fire and small brush fire. Just be aware of it's limits. A fully engulfed vehicle has the potential for gas tank explosion and debri. Working with livestock, I also carry a veterinary first aid kit and restraint equipment. A word to anyone carrying extensive first aid- prescription drugs and hypodermic needles are just that. Keep a valid prescription with the meds.