Sometimes you have to deal with more then just a flat tire. You could get stuck in the mud or there could be a natural disaster. So in addition to the basic car repair kit, an emergency kit  can easily deal with stressful events:

•Fire extinguisher (5 lb., A-B-C type)
•Flashlight and extra batteries
•Battery-powered AM/FM radio and extra batteries
•Compass and road maps
•Shovel
•Sack of sand or cat litter (for tire traction)
•Bottled water
•Non-perishable high-energy foods, such as granola bars, raisins or peanut butter
•Extra clothing to keep dry
•Blankets or sleeping bags