Technically, I think the expansion of castle doctrine to the auto may have actually made rack carry illegal. Not that a single cop would mess with me up here for a racked rifle but from tall to jax and all the way south could a different situation...
790.25 (5)(5) Lawful Ownership, Possession, and Use of Firearms and Other Weapons
Florida law allows any person who can legally own a firearm to carry it in his/her vehicle without a license or permit, even loaded, so long as it is "securely encased" and "not accessible for immediate use" (and the statute plainly states that simply placing the firearm in an unlocked glove compartment or briefcase is sufficient, for example). Refer to the Car/Gun Law paragraph above.