We're spending four days in Lucca and will be traveling from Firenze where we are arriving on the train from Rome. Our plan is to take day trips from Lucca to other towns in Tuscany. Should we rent a car in Firenze and drive to Lucca or take the train or bus to Lucca and rent a car there? How far are the Europcar agencies from the train station in Florence?

I certainly wouldn't pick up a car in Florence. Its historic center is the worst place to drive. Access is very strictly limited.

However, you may not need a car. What places do you want to visit? Lucca is not terribly central for the usual Tuscan car tour.

I'm afraid I'm not too much help with your question. But I would like to know what your plans are for Lucca. I'll be there for a night and a day and would like to hear your plans.
Thanks

Siena would be a more central town. To make day trips to beautiful towns like Montepuliciano requires a car. It's expensive to park the car at hotels, but there are large public lots near the stadium in Siena.

In Firenze, we picked up our Europcar rental car on Borgo Oggisanti (I think there are other rental agencies along the same street). It is fairly close to the train station. While getting out of the city was somewhat difficult, we had good directions and a good navigator (me). I think you should train to Lucca and rent the car there. But another question: do you have a free or inexpensive place to park in Lucca? If you are staying within the walls, parking may be an issue.
As for Lucca vs. southern Tuscany, I love northern Tuscany. It is less touristy - more "real life" Italy. You can do many car trips from Lucca - San G, Volterra, the Chianti, Pisa, Cinque Terre.

Which Tuscan cites do you plan to visit--that is key to your question.

Thanks everyone for your input. We have friends who stayed in Lucca and found it very versatile for visiting other places, as well as very charming. A day trip to Siena and even to the coastwe're told by them is very doable. We're staying inside the gate and the hotel apparently offers parking nearby. We'll see I guess when we get there. There are always bus trips I guess to nearby places also, but I really wanted to drive around a bit and enjoy the countryside. We were in the region a few years ago and really loved driving around and seeing the beautiful scenery as well as tasting the local wines, etc.

I love Lucca and you will too, but a 4 hour RT drive to Siena does not make sense to me.

There are a number of villas you can visit around Lucca. Here's a link: www.initaly.com/regions/villluca.htm. However, I see the entrance fees are in liras so the site is well out of date. The TI in Lucca should be able to givbe you more up-to-date info if you're interested.