The annual drive out deals from Florida to the US Northeast from April 1 - May 31st are back with most of the major car rental companies. Typically any size vehicle up to a full size is $10/day with unlimited mileage. Good option if looking for a cheap one way flight from Buffalo to Florida for example and then drive back.
https://www.alamo.com/en_US/car-rent...-20150531.html
http://www.enterprise.com/car_rental...cpCode=FLDRIVE
http://www.avis.com/car-rental/deals...hp_s2_onewayFL
https://www.hertz.com/rentacar/speci...dadriveout.xml
https://www.nationalcar.com/en_US/ca...-driveout.html
https://www.alamo.com/en_US/car-rent...-20150531.html
http://www.enterprise.com/car_rental...cpCode=FLDRIVE
http://www.avis.com/car-rental/deals...hp_s2_onewayFL
https://www.hertz.com/rentacar/speci...dadriveout.xml
https://www.nationalcar.com/en_US/ca...-driveout.html