We are in Marbella now and ended up renting from economy car rental in the end. I really wish I had stuck with a name brand company. The extra you pay for turns out is for good reason.
We had trouble finding our luggage and waited in line to report it as lost for a good while before finding out that the luggages arriving on transfer go to a special carousel. So almost an hour after landing, we started to look for the car rental desk. Economy does not have a desk with all the other car rental companies at the airport but I was glad to see that there was someone holding up a sign with my name when we exited the airport. We followed him for about 1/4 mile schlepping all our luggage, found the car, loaded it up only to find out that he was not from economy car rental, but from yougospain, even though they had never confirmed my reservation so I thought it was cancelled. So we had to walk back to the airport, look for the guy from economy, who was nowhere to be seen. After fifteen more minutes and asking many people if we could use their cell phones and being refused, we just turned on our U.S. phone and called him. He had left the airport. He agreed to come back and we had to schlep, one more time, to a location 1/4 mile away to find the car. The car was old and full of scratches but at this point we didn't care, we just wanted to be on our way. But just one more thing, he wanted to get paid. But I had already prepaid, I said. Ah! This was for the gas! At that point I realized why there was such a long thread about car rentals in Malaga.
If I were you, I would stick with hertz and take a cab to the airport from the Granada location in town.