The B&B is within the city walls in zona traffico limitato, but in principle accessible with a car to unload the baggage. But attention: if you follow your navigation system you will end up directly in the central pedestrian zone with hundreds of people walking there, looking at you strangely and perhaps thinking that you are a real rowdy. This happened to us and we had tremendous difficulties to find a side exit from that zone leading us back to the main road circumventing San Gimignano. I strongly recommend to directly drive to parking lot P3 (15 EUR/day) and walk to the B&B with your luggage (5-8 minutes). Alternatively if you want to drive close to the hotel you should ask them to send you their instructive map how to access the street next to the B&B (you cannot enter Via Diaceto). If you have this know-how access is rather straightforward (albeit still leading you through a ZTL, but no video cameras installed!). I frankly do not understand why the B&B does not do that automatically upon reservation as many places do in Spain (which I just booked for our next Easter vacation). This is a definitive lack of service. Another less comfortable issue is that check-in starts only at 15.00h.
Another service problem is the fact that they do not have a computer available with a printer, e.g. to make a check-in for your flights. WiFi is however functioning very well.
This B&B is simply superb! Modern comfortable and quiet rooms and a beautiful large (kind of roof top) garden with tables, chairs and even loungers. Fantastic place to have a drink, enjoy a bottle of wine or just lie in the sun while admiring the towers of San Gimignano only 100 m away. Breakfast was good and had the level which you generally find these days in Italy: fruit juices, cereals, ham, sausage, cheese, sweets, coffee or tea.
I cannot imagine a better place to stay in this town – despite of the small troubles in accessing the place and some small service deficiencies.