If your glove compartment is home to fast-food ketchup packets, service receipts, expired proofs of insurance, or other detritus, clean it out and restock it with the following items:
Registration and proof of insurance (but not the title, which should be kept in a safe place at home)
Owner's manual (demystify those flashing dashboard symbols)
Small flashlight (instead of worrying about batteries, opt for a hand-cranked flashlight, which gives an hour of light per minutes of cranking)
Swiss army knife (you never know when you might need scissors, a can opener, or a scewdriver)
Tire pressure gauge (correct tire pressure improves gas mileage and prolongs tire life)
A cell phone charge
Emergency contact (insurance agent, tow service, local police)
Wet wipes (for sticky fingers, spills, or to wipe your hands after a visit to the pump)
Pen and notebook (for recording information in case of an accident)
Flickr photo by simongreenuk
For more cleaning tips, check out What's A Disorganized Person To Do?
