Car travel can be miserable, or you make the best of it and be comfortable. Whether you have kids, or one passenger, or even just yourself, there are things you can do to make it better.
Car Travel - Make the Trip Bearable and Fun!
For car travel, take snacks and meals that are easy to prepare and eat (and not too messy). Try to be healthy about it - it will help keep down the throwing up issue. Pack nuts, popped corn, apple and cheese slices, orange sections, and raisins for snacks. Take a cooler for drinks, and water bottles filled with water (if you pack bottled water, keep them out of the sun and heat). Put sandwiches in the cooler, or take bread and sandwich makings (peanut butter, jelly, honey, lunch meat, lettuce, tuna salad, condiments, etc.).
Check the car over before the trip - oil, tire pressure and tread wear, windshield wiper fluid, air conditioning, heater, gas level and such. Fill up all that is low.
Make sure you have a minimum of tools and aids to get you a quick fix - tire changing tools, spare tire, compressed air to fill a tire, phone charger, jump start cables, etc. You may consider making sure your AAA or other roadside help programs are up to date. Most other tools are fairly useless in electronic cars - not much you can fix if in the programming, but they might come in handy for other situations while traveling.
Depending on your trip, you may want to have sunglasses, spare clothes, boots, gloves, jacket, flares, shovel, flashlight, raincoat or poncho, duct tape, First Aid kit, sand bags (handy for traction in ice), some camping equipment if you need to warm food or warm the car, nonperishable food, a can opener, etc.
For diversions and entertainment, you might want video or audio tapes/CDs/DVDs (perhaps a book on tape), downloaded podcasts and music, kid toys and games, pet needs, etc.
For comfort, you might need a back pillow, pillows for laying down on for breaks, neck pillows etc. Blankets and other items you can think of can come in handy.
Make sure to take occasional rest stops to stretch out Take turns driving and sleeping (or make sure you need to keep the driver alert and not drift off), and perhaps take a thermos of coffee. If you stop off to take a nap, try to find a safe place - a rest stop, a motel parking lot, a well-lit area, or some such place that you can feel able to honk for help.
If you rent a car, check for dings and dents before you take off - so you don't get blamed for them when you return the car. If you return the car to a different rental center than you took the car from, check for cost differences between rental companies.