Car rental in Sevilla?

I rented at Santa Justa from Europcar. Their office is in the station opposite the escalators to the train tracks. (It took me a really long time to find them because I didn't know that.) Then you have to go through the station and down to the parking lot to take the car. But you have to validate the parking ticket in a machine on the way and then you have 30 minutes to leave the lot (after loading up and inspecting the car). If you take longer, you have to go back to the machine and pay a small sum for parking. I did not have GPS or good driving instructions so it took me quite awhile to get on the highway I wanted in the direction I wanted.

I've never rented at the airport, so I have no clue if it's easier there.

Had I known where the office was and had GPS, it would have been a lot easier at the train station.

We returned a car to the train station in Seville and had no problem with navigation. It was several years ago so I went the old fashioned way - I used via Michelin and printed out the directions. It may have been low tech, but it worked like a charm. I rented through Auto Europe but am pretty certain the actual agency was Europcar. My memory is that we were on city streets for a fairly short time after being on an interstate from Southern Spain. With either GPS or written directions it should be an easy process.

Thanks to both of you!

I typically avoid renting at airports, the price is generally better renting in town. There will be plenty of car rental agencies in town, I generally pick one that's closest (normally walking distance) to my lodging.