Service before the swamp, not in it
The towns that carry real service are the highway towns: Naples, Ocala, Lake City, Homestead, Daytona Beach, Brooksville. Ochopee, Sumatra, Astor and Salt Springs do not. Big Cypress gives its ORV office a phone number rather than a garage, and the Apalachicola district offices at Bristol and Crawfordville are ranger stations.
Ask for a water and corrosion inspection rather than a tune. Differential and transfer case breathers, wheel bearings, brake hardware, electrical connectors and anything with a rubber boot are what a Florida trip ruins. If the vehicle has been in brackish water on a dike road or a beach approach, say so, because the follow-up is a rinse and an inspection rather than an oil change.