san gimignano is 2 days too much
 

is this too much time to spend in this place we dont have a car

It's good to stay there at least overnight, because you'll enjoy it more in the evening when all the tourists arriving on day trips have left. We were there for 24 hours (mid-day to mid-day) and it seemed just about right.

thanks, do you know if we can rent a car in town if we are there and also is it possible to do any wine tours.

I didn't see a car rental in the town itself (most of the walled city is closed to traffic), but you could call autoeurope to find the nearest rental agency. And maybe bus it to the rental location?

Google for the San Gimignano website. It has lots of information on it. It may help with tour or car rentals.