Here's another person's version of a Car Kit. Please look over this post and the one before it and decide what you should have on hand for a car emergency.
Bag of sand
Change of clothes for each family member
De-icer (road)
Extra batteries
Flashlight and batteries
Jumper cable
Note pad/pencil
Red triangle flat to go on antenna
Safety flares
Space emergency blankets, 1 per family member
Tow rope/tow strap
Transistor radio and batteries
Walking shoes and socks for each family member
Windshield ice scraper
Winter hat, coat, gloves for each family member
