You can also get a smart car for as little as $100/mo if you don't drive too much. If you're only looking for a small commuter they're both good options. That said, both the smart and fiat are fugly. You have to have a high tolerance for looking like a dork (not in a good way) to drive either.
The Smart FourTwo really suffered in its translation to the North American market. They dropped in Canada about 2 years earlier and got like 70MPG. Then they come to the US and that number gets cut in half. I'm suspicious of any car that gains in performance when you add a motorcycle engine. Edited to add: I'm now rocking an Android phone because the same day T-Mobile tried to sell me a fully loaded iPhone 6 plus for $59 a month, Nissan tried to lease me a versa for $79 a month. Something in my skull cracked. Phones should be an order of magnitude cheaper than cars. Always.