We are thinking of renting a car for the day to drive to Santiago de Campostela. Has anyone else done that?

Compostela is not far away from Vigo. Renting a car is good way not only to visit Compostela but to visit coutry following small roads off the most common path. Galicia has a wonderfun landscape, The rent a car company will provide you with some route that match all your expectations.

Nice option to come to Santiago, where I live, but take care that traffic in Vigo is rather confusion and a hassle. So be careful.