Can't trust these guys
The car was actually very fine. What troubled us was that the clerk kept pushing additional insurance and lied to us, by saying there were many tolls on the way to Key West and that it was "definitely worth it" to pay 8 USD per day for unlimited tolls. I would not trust a company that lies like this to its customers. This is just terrible service. I strongly recommend against renting any cars with Sixt after this experience.