driving in Florence is not the easyest thing in the world, but...it's possible. If you reach the city with your car, you need to follow the direction to Via Santa Caterina d'Alessandria, then becames Piazza Indipendenza and then via Nazionale. When you are in via Nazionale, the first street on the right gets to via Guelfa, if you follow the street, at the end, there is a small square ( piazza del Crocifisso ). Immediately on the left, there is the parking where you can drop off the car: Parcheggio Palacongressi. Once there you can walk in via Faenza for 50 metres and find Hotel Mario's at the number 89.
In any case, the parking aware the police that you have the car parked in their garage, so that, even if you made some mistakes coming to centre ( if you pass in the reserved bus street or if you entered in a protected area ) you don't have to worry about something.
So, now it's time to visit Florence and to book at Hotel Mario's.
via Faenza 89,