Probably the best road to Vitoria Gastéiz leaving the motorway at the N° 12 Outgo.
Make a stop for lunch at AZPEITIA, the place where Saint Ignace of Loyola in born. Visite the church. So Marvellous. Have Tapas on the main city place. Very cheap. It would cost you 12-15€ for 2, drink and food.
Enjoy the lovely country road ultill you reach the speedway, 30 km fast road before Vitoria.
Make a stop for night in Vitoria. Beautifull city, visit the historical center (the cathédral, better bookin the day before), plenty of bars.
Great place. Unforgettable.