Here's a two-week alternative, which could include a few car days in southern Spain near the end of your trip: Start in Barcelona (two days); train to Madrid (five days total, with two days in Madrid and three for side-trips to Toledo, El Escorial, and Segovia or Avila); train to Granada (two days); bus to Nerja (one day, could rent car here); both Ronda and Arcos for drivers, or just Ronda by train (two days); to Sevilla (drop off car, two days); and then train to Madrid and fly home.