We didn´t have a car, so I don´t know. But having seen the amount of cars in the streets and the squares around the hotel I suspect there might problems to fins a parking space. Maybe the reception can give you some useful advice?
there's no private parking. You can leave your car in the street in front of the hotel or the nearby square.
I came to the hotel by taxi - not by car, although the hotel is delightful it is not adequate for a wheel chair. This needs to be confirmed with the hotel. I understand that there is limited allocated parking in the inner courtyard which is shared with other residences this again could pose a problem as access to the hotel is from the front not from the inner court area - this again needs to be confirmed with the hotel.
Get an answer from Manganelli Palace Hotel staff and past guests.