Out of all the popular cities in Spain, Las Palmas de Gran Canaria is the cheapest city to rent a car in at just $5/day. Renting a car in Las Palmas de Gran Canaria is 50% cheaper than renting one in Madrid where the per day rate is around $11. Other fairly inexpensive cities in Spain to get a rental car in are: Valencia ($6/day), Santa Cruz de Tenerife ($7/day), and Puerto del Rosario ($7/day). While these cities typically have cheaper prices than the rest of the country, travelers looking to rent a car in Barcelona should expect to spend around $9/day on their transportation. The most popular city to rent a car in Spain is Barcelona.