The thing with FL is you can see 2 nearly identical rigs in a parking lot in the same town.
One will be rust free...the other a rust bucket.
Florida is (usually) a very wet state regardless of location. Just because you don't 'see' rust on a rig doesn't mean it's not there.
PLUS with so many non native Floridians you don't know if the rig is a 'native' or not which means it could have come from anywhere and anywhere can be part of the rust/salt belt. I have lived in FL for nearly 30 years...been jeeping for 10. We've owned 7 XJ's and only 4 of the 7 were actual Florida natives.
Just look them over well but the FL XJ's tend to like to rust inside more than outside...again what you CAN'T see at a glance. Floorboards, rockers, rear cargo floor, etc. THey are just as likely to rust in these places in FL as anywhere else. 2 of my MJ's had swiss cheese floors...the 3rd did not. All had been FL trucks.