That depends on where you’ll be wandering. Downtown Tunis, about 4 miles from Tunis Airport (TUN-Tunis - Carthage Intl.), can be difficult to drive around. Make things easy for yourself by renting something small, fuel-efficient, and simple to handle. That being said, Tunis is a popular base to explore many of the sandy shores in Tunisia. If your trip is more about tearing down the open road, then you may prefer something with a bit more trunk space and legroom. How about a full-size car or a standard SUV?