Well I can't fit anything else in my truck when I go to and from work. Our company has a policy on what to have in the car.
Flashlight, 3 sets of reflective triangles, flourecent vest, disposable camera, accident reporting kit, extra set of clothes, blanket, fire extinguisher, first aid kit, and a list of evryone you should call if you have an accident.

I use to carry a complete distributer/coil and carb until i bought new stuff.....