The car service to Rome left @ 9am from the hotel and returned @ 6pm. The drop off and pick-up are in via Ludovisci, a short walk away from the Spanish Steps.
Although I am gold with SPG, I did not inquire about an upgrade when I checked in. There was absolutely no verbal recognition of my status, but in the room was a note from the hotel manager, with a bottle of wine. The room was quite large by European standards, and as mentioned, the bathroom is all marble. We had access to a very small balcony from our room, which was an upgrade possibly?
I would not have been happy here without a car, although I am sure that a taxi would work for short trips to nearby restaurants. The old town is ~ 4kms away and up a fairly steep hill, it is where all the recommended restaurants are located. We enjoyed La Locanda in particular and would have eaten at La Torre but it was closed the Sunday evening we tried it.
We particularly enjoyed our day trip by car to Tivoli, to see the ruins of Hadrian's villa and visit the gardens of the Villa D'Este. We have traveled quite a bit in Italy, and I have to say that the gardens at the Villa D'Este are stunning; they are a UNESCO world heritage site and justly deserving of the designation.