If you rent a car abroad while visiting Spain or countries outside Western Europe, you may need to secure an International Driver's License from your local auto club.
The license is valid for one year and requires two passport-size photos and a nominal fee ($5-$15).
It is issued automatically if you present your valid state driver's license.
Don't leave your U.S. license at home, however. You should carry both your state license and your International Driver's License.
Before you decide to drive while abroad, remember that a car can be very isolating. Your reality becomes the inside of the car, not the culture of the country.
Gas is expensive; it's hard to find a parking space; and you have to deal with unfamiliar driving customs and foreign traffic laws.
Car accidents are the leading cause of death for travelers. The biggest challenge is driving on the left, which is the custom in the United Kingdom, Australia, Hong Kong and several other countries throughout the world. Allow at least a week to get used to driving on the left.
When driving or getting around using public transportation, think in kilometers, if that's the standard measure. It's much easier than constantly trying to convert (a kilometer is .62 of a mile).
Some local rental agencies are cheaper than the big name places. Also, some agencies will not rent cars to people over 70 or under 25.