Thank you Karen!

@daria The driving in Costa Brava was fine. We were there before the season began so parking was not a problem anywhere we visited except Cadaques took some looping around. (Tip: park once by Dali home and walk back and forth to Cadaques if you don't mind what seems to be a 25 minute walk each way. This would have saved us a lot of aggravation.). Summer presumably more traffic and potential parking woes.
I am by no means a Spain expert but San Sebastián to Costa Brava seems like a challenge by public transportation.
Also, I would add a bit on to google maps driving times. We found that the unexpected detour or missed turn or traffic added about 25 percent to the time, give or take.
Have a great trip!

Thanks for this report. I will be there for business and amnlooking for ways to maximize my free time. I really appreciate the reading recommendations! I do love to read about my destinations before I go!