With so many car rental companies to choose from, the best place to look for a car rental in Spain is on an aggregator site. These feature all the big car rental companies, including Hertz, Budget, National, and Alamo, and show the prices for a number of different car classes in an easy to read table.
Renting a car in Spain will never be your cheapest option, but it might be the most convenient. The basic rental will cost more than your train or bus ticket and then on top of that, you'll be paying for road tolls and petrol.
Renting a car is essential if you want to explore some of the harder-to-reach regions like the Alpujarras, the Rías Bajas (to the west of Santiago de Compostela) or the region around Cadiz and Tarifa.
However, if you're going to be sticking to the big cities in Spain, renting a car is a bad idea. For a start, parking in most big cities in Spain is a nightmare. A journey that would normally take 15 minutes by car often takes double that as you look for a parking space. Another problem is traffic – it's a well-known fact that you can see traffic jams in Madrid at 5 a.m.! Also, if a city is big enough for a car to be handy, it will have a metro system. Madrid, Barcelona, Valencia, and Bilbao all have a metro and one is currently being built in Seville. The cities that don't have a metro system – and that includes Granada, Santiago de Compostela, A Coruña, Toledo & Segovia – are small enough to not need a car.
If you decide to rent a car in Spain anyway, you need to know a few things.
By law, if you do not have an EU driving license, you are required to have an international driving license. Most rental companies state this in the T&C’s. However, they may or may not request to see your international driving license when picking up your car rental (but it's nevertheless advised to have one).
18 years of age is the minimum legal age for driving in Spain. Please note that most car hire suppliers require a minimum age of 21 in order to hire a car.
In addition, drivers under the age of 25 can be subject to a “young driver fee”, to be charged by the supplier at the time of pick up. So your rental car in Spain just got more expensive!
Spanish speed limits: 50 km/h inside towns, for main roads with only one lane it's 90 km/h and on highways you can drive up to 120 km/h. Driving is on the right-hand side of the road.