Whether a regular road warrior or just a casual day time driver one should always be prepared for most any potential problems you might come across while driving. A little bit of planning ahead and carrying a few extra things in your car can go a long way if you ever find yourself in an unfortunate situation.

We all hope to avoid them but sometimes that is not very easy to do. Along with your vehicle registration and insurance, keep a small notebook and pen. Consider also carrying a camera to take pictures of the accident. Search local shrift store for something cheap if needed be.

Winter weather may cause you to be stranded by the road, nice weather may find you stuck in bumper to bumper traffic. Don't be caught unprepared. To be prepared for cold weather carry a blanket in your vehicle. The blanket does not have to be very big, just something to provide extra warmth if you get stranded. Also be sure you have and can find an ice scraper. No matter the weather consider carrying both food and water in your vehicle. Food being something that won't become inedible very soon, chips, trail-mix, etc. Anything to help tide you over if you get stuck. Along with water to drink, consider a bottle of general water. This can be used for cleaning off your windshield, cooling off an over heating engine, or even cleaning mud off your shoes before entering the car.

First Aid:
First aid kits are certainly good to carry with you. Often a small kit bought at the store can contain most things you might need. If those are not easily obtained make your own. Most important is; band-aids, and an antibacterial cream. Both vehicle accidents and everyday things can cause injuries that may call for first aid.
Along with First aid kits is roadside emergency kits. If you can get one they can hold many things that can be helpful in the event of an accident or flat tire.

Other odds and ends that may come in handy are:
Paper towels, these are not only good for cleaning up spills but also for checking car oil. Along with that is baby wipes or something like it. When kept in an enclosed container they can stay damp and be used to clean mess off your hands.
Change of clothes, if you have a spare change of clothes you can leave in your car you can be prepared in case you find your current clothes dirty when you are headed to something important.
Gas can and jumper cables, they won't be useful until they are VERY useful!
Busy items, this can be coloring books and crayons for the kids or a book of some sorts for yourself. If you are stuck in stopped traffic a book on tape or puzzle book can make the stop not feel so long and therefore keep your stress level down.

I personally keep many of these items in my vehicle at all times, some I don't use often but they are extremely helpful to have sitting there when I do find myself needing them.
Whether on long trips or just running to the store, you never know when you may find yourself needing these items. A little bit of planing ahead can save you a lot of stress and trouble later.