Wanted to circle back to this, having just gotten back from this trip. We did end up renting a car because we found one for about 50 Euro total (electric car, pre fuel, direct dropoff at the airport). For the convenience we felt it was worth it, especially since having an electric meant we had free parking in any blue marked spot on the street.
The drive was beautiful and took us up the hills/mountainsides along the coast. Not a single tunnel as indicated by other posters (though we saw the train go thru many tunnels on the same route). There were several "miradors" (overlooks) along the coast to stop and take in the view. Reminded me of the coastal highway 1 drive in California, but much much shorter (only about 30 minutes) and felt less windy. We were grateful to have the car so we could go to several other small nearby towns and explore the area thoroughly before leaving again.