I found that from a reliable source: Rental car companies need to move their cars out of Florida to other locations where they are more likely to be able to rent them during the summer. Alamo is offering rentals for as low as $4.95 per day for doing this. Rental pick up must be between April 1-May 31, 2017. If you fly nonrev to Florida and need to return from elsewhere in the country (Via milenerd) it might be worth to try.
