is returning the car in Siena and taking a fast? train to Florence any
better plan? Sounds like we did not leave enough time in this leg to
take this flight without stress (with or without a fast car - the
driver is lacking!) before I change "something" - thank you for your
insight.
There are no fast trains from Siena. It's a regional train to Florence (1hr 34 min) but that just gets you to train station in Florence, so you'd still need to get to airport.
It's just over a 1 hour drive from Siena to the Florence airport. Just get going early and you should be fine- I would leave Siena at 6:30/7 am.
You need to be at terminal checking in by 9 am.
Let's see what Roberto says- he knows the traffic in the area very well. Please let him know what day of the week this will be.
Alternative plan would be to drop the car in Florence the day before and spend your last night IN Florence. From the center it is a quick taxi or tram ride to the airport.
Or drop car in Siena if you have no need for it there- then head to Florence hotel night before departure. (IOW- I wouldn't want to try to take train from Siena to Florence then to airport on departure morning. Too risky)