It's never a great idea to neglect your ride's basic maintenance, but to head out on the open road without even a cursory checkup is asking for it. And sure enough, almost 10 percent of the country ends up on the side of the road every year: AAA says it received nearly 29 million calls for roadside assistance in 2011 due to customers failing to "properly maintain their vehicles." For instance, 20 percent of those callers had a dead battery – a dilemma a simple inspection would have easily diagnosed well before it felled a driver in the middle of the Mojave.
So before pulling out of the driveway (and ideally a few weeks before your trip in case anything major comes up), make sure to do the following: Check and change your oil, coolant, and other fluids; inspect your tires (including your spare tire); and replace your fuel and air filters. Remember, it's better to resolve such problems at home, where you're comfortable with the mechanic diagnosing and fixing them, rather than on the road, in the middle of nowhere, with a mechanic that knows he has you over a barrel.