Is Florence Train station easily accessible with a rental car?

My preference would be no. I would be more inclined to find a smaller town outside of Florence to rent a car. I do like the advice given in other threads to rent in Chuisi, do Tuscany, and either save Florence for the end, when you have dropped off the car, or take public transportation in to daytrip to Florence. Even the smaller towns in Tuscany are best approached by parking in the lots on the outskirts and taking public transport into town, lest you get some surprises in the mail a few months later.

See my answer to this question in your Florence to Venice By Rail question.

No, the Florence train station is not easily accessible by rental car. This is the same answer as Larry gave on your other topic thread, for the same reasons. Here's a map of the Florence ZTL's http://www.bella-toscana.com/traffic/firenze_ztl_map.jpgThe 5 colored areas are the ZTLs. Technically, the station appears to be outside the ZTL (station users park under the station during the day) but note that the station is surrounded on 3 sides by the ZTL. I estimate your chances of successfully driving your car to the station without violating the ZTL is maybe 10% or 20%, that's just the way driving in Florence is. The locals license numbers are in the city computer system so they don't get fined.

To avoid driving in the center we used AutoEurope & picked up our car on the other side of the Arno at Via Del Gelsimino, Florence. We took a ten euro taxi from the train station. This location leads right onto the Wine Roads. We returned the car in Chiusi which was easy.