Parking, the bane of all travelers driving around Spain, is no different in Girona. At least the hotel provides on-site parking, even if at 18 euros a night it isn't particularly cheap. But, be prepared to have to drive down 1-3 underground levels of tight turns and cramped spaces to get to your parking spot.
We travel to Girona a couple of times a year to visit family and have always stayed at the Gran Ultonia. It isn't the best hotel in the world, but it may well be the best in Girona. As usual, the staff were professional, the hotel and the rooms were clean, and the free Wifi worked well. The hotel is located near the old part of town and all the sights are within an easy short walk. There are also a large variety of restaurants nearby to chose from. If you would rather not pay the exorbitant breakfast buffet prices, there is an excellent little coffee bar attached to the lobby where you can get a simple breakfast for cheap.