There was always a pink blanket in the trunk of the family car when I was growing up. It took up a lot of space but could never be removed, because what if the car broke down in winter? We would all have to huddle under the blanket while we waited for help. Driving without a blanket is just asking for trouble.
This never happened, of course, and I didn't carry on the tradition. But I always think of the trunk of my car as a place to carry emergency essentials. I wouldn't go anywhere without jumper cables, and I've used mine several times over the years - sometimes to be a good Samaritan, sometimes to ask for a jump myself.
Now that I have kids, there's a lot more going on than emergency gear. It's not like I'm going to leave home without nappies, nail trimmers, or approximately 37 baby dolls.
So what do you keep in your car?