I spent a long time reviewing car rental companies for our holiday in Spain. I settled on SIXT who were excellent from start to finish. I collected the car from Girona train station and dropped it back to Girona airport. The car was a much better specification than I expected and was parked in a nearby parking garage (allowing us to checkout of our hotel and walk to it). There was no hassle about having to purchase their insurance waiver or any extras. Dropping the car back at the airport was also very simple and quick. The kind SIXT employee took us via a shuttle bus to the airport terminal too. I can't recommend them enough!