why hertz?
 

9 times out of 10 when renting in Europe, Sixt has worked out significantly cheaper than Hertz (usually cheaper than Avis too). And there's their low-cost branch (called Sixti) that rents out Smarts from 5 euros a day!
And driving in Italy is fine, only Rome has a very serious congestion problem...

Hop on the train to Florence. Should take about an hour and a half. Florence in March is great. Any questions shoot me an email or pm. Enjoy Italy!

Thanks for the tips - as for why hertz? I like the general consistency of Hertz, but you're right - I should consider other agencies - I'll check it out.

Thanks!