Don't bother with the car! Public transportation will get you EVERYWHERE! And besides that way instead of paying attention to the road and making sure you turn on the right street or the right exit, you'll be able to take in the scenery and rest from place to place! (which no matter how young or old, in Spain, its ALWAYS a good thing to catch some rest when you can- as one always needs PLENTY of energy! )

I have the name of a hostel in Santiago, but I have to search for it. I have their business card somewhere...I think. I'm not sure if it had an elevator, which with many of the buildings especially near a historic location, will not have, but you can probably ask for a room on the closest floor to the street. I will search and post later if I can find the name of the hostel.