Keep a stash of safety gear in your trunk just in case of emergencies. Bottled water (a couple of gallons or a case of individual bottles), battery cables and a first aid kit are the basics. Have a spare tire accessible (and check that it’s full!), and make sure you know how to change it if needed. Nonperishable food such as granola bars, blankets if you’re driving in winter weather, and a flashlight should also make it into the trunk.