When we arrived, we were told that the reserved car model was unavailable. Originally, we were supposed to pick up the car at Terminal 1 of the airport, but we ended up waiting for 1.5 hours on-site for the car to be transferred from Terminal 4. We've rented cars abroad many times before, and in such situations, companies usually offer a free upgrade. However, this rental company told us that upgrading would incur extra costs. Not sure if this is due to Spanish rigidity or just this company's policy.