The Open Carry law did not change.
SB234 was intended to change the law back to allowing open carry as it was before the State-wide concealed carry law was passed way back when.
There was hoplophobic resistance and some unethical (possibly unlawful) shenanigans by a few Sheriff's/lCongress Critters trying to scare the Legislature and instead of doing the right thing and just pulling the bill, they allowed it to become what you see in SB234.
Which is nothing really, other than some very confusing language. Saying that a 'breif' open display of a concelaed firearm was not illegal. Well, here is the shocker, IT NEVER WAS BEFORE!
OK, now with that over with....
790.25(5) is the specific section that talks about firearms, other than pistols, in automobiles.
5) POSSESSION IN PRIVATE CONVEYANCE.—Notwithstanding subsection (2), it is lawful and is not a violation of s. 790.01 for a person 18 years of age or older to possess a concealed firearm or other weapon for self-defense or other lawful purpose within the interior of a private conveyance, without a license, if the firearm or other weapon is securely encased or is otherwise not readily accessible for immediate use. Nothing herein contained prohibits the carrying of a legal firearm other than a handgun anywhere in a private conveyance when such firearm is being carried for a lawful use. Nothing herein contained shall be construed to authorize the carrying of a concealed firearm or other weapon on the person. This subsection shall be liberally construed in favor of the lawful use, ownership, and possession of firearms and other weapons, including lawful self-defense as provided in s. 776.012.
Anywhere - Gun rack, back seat, heck in your lap if you want.