It's interesting that they point out Ohio's bizarre law requiring "in plain sight" while in a car, else unloaded and locked away.
If such a law applied to me, I think I'd rely on the old "briefcase carry", commonly used before concealed carry was legal. With your pistol in a briefcase on the seat beside you, it's readily accessible -- but with a quick spin of the combination dials, it's locked. Nothing inside is accessible to you, so there's no legitimate reason to search it.
Kevin