FL law on concealed folders is VERY vague. any knife "other than a common pocket knife" is how it reads. i've had (fellow) LEO's tell me a one handed folder with a clip is NOT a common pocket knife, that only a little slip joint or lockback is a common pocket knife. i know other LEO's who feel a one handed opener with a clip IS common, but auto's are NOT. personally, i wouldn't risk it and i've always argued that carrying them is legal.
here's a interesting little tid bit, though: the statute only covers carrying knives CONCEALED. so, while an auto is (arguably) illegal in your pocket, it is CLEARLY legal if open carried.
FL has NO statute banning autos, the "self propelled" knife statute was ammended for clarity. they are only covered under the concealed weapon statute.
easiest thing is apply for your concealed weapons permit, as long as you qualify. then you're good to go on (virtually) whatever you feel inclined to carry.