The family wagon has a first aid kit, a mega box of wipes (for the inevitable number 3) and a fire extinguisher. I always take snacks and a drink with me, but that's because I refuse to buy bottled water

The 4WD is a lot like little_mrs plus a fire extinguisher- you'd be surprised when it comes in handy, we've had to use ours twice (not the same one of course) once at a car accident and another when we came across a car fire (stolen) in the bush near our place. Hubby got out and stopped a running grass fire with it! Oh, we also have a tarp and rainjackets in the 4wd for if we need to change a tyre in the wet