Seeing the other thread on household stuff made me think of this.
I have enough stuff in my car to prepare for most eventualities as it's the family car. Hence there's usually a 24 pack of water, 15 assorted coats and a selection of hats, scarves etc and various food items. However, DH needs a bag which is kept just for this eventuality I think.
What should it contain?
Drinks
Blanket
Hat
Gloves
Food
Book
Any other ideas?