A sleeping bag and a pillow should be standard equipment in any car while driving in the countryside both winter and summer. If you are a long way from civilisation and you get trouble with your car of any kind you will need the pillow and the sleeping bag to get rest and keep warm. This is specially important when you drive in the winter, and even more so if you drive in the mountains. If you get snowed in it might take a long time to get help. If you run out of petrol you will soon find yourself freezing in your car pretty soon. And leaving your car in a blizzard is a bad idea. Having your sleeping bag and pillow, warm clothes with you along with some hot drink on a thermos may save your life.