Just a heads up. Got a credit card charge from rental car company over a month after returning a rental car in FL. Turns out in Tampa on the Selmon Crosstown Expressway, there is now NO way to pay cash for the toll. If you don't have a transponder or a "we bill you" account set up (which I don't believe is possible in a rental situation), your license plate is photographed and the bill sent along to the rental company. (The charge from the rental car company was the $1.50 toll plus a $25 fee) This was assuredly NOT explained to us when renting the car and NOT clearly marked on the expressway.
The Thrify rep said that all of FL is going cashless tolls in the near future. Will have to figure out what to do when next visit to FL comes along.