There are many companies that offer car hire at Madrid Airport (MAD) in Spain.
Airport car hire is offered by both large international rental car companies and regional Spanish ones.
These companies offer cars at Madrid Airport: Avis, Enterprise / Atesa, Europcar, Hertz, and Sixt.
Whichever you choose, make sure to shop around for deals online before booking. There are many car hire voucher codes that can get you good discounts on your rental car. Additionally, if you don’t need a car for your whole trip, consider hiring one in the city instead of at the airport. That will save you money on the airport taxes.
Additionally, read the fine print on your car hire contract to make sure you understand what additional charges you may incur. Some companies charge extra for petrol, exceeding a maximum distance limit, or picking up or dropping off your car at the airport after hours.