I thought Ohio was the weird state... you are correct, zukiphile.
http://codes.ohio.gov/orc/2923
You want to read sections 2923.12 AND 2923.16
Without a permit you cannot have a loaded firearm in the vehicle AND all rounds must be removed from the magazine to be considered unloaded. That law does NOT apply to rifles, though.
2923.16 Improperly handling firearms in a motor vehicle.
(A) No person shall knowingly discharge a firearm while in or on a motor vehicle.
(B) No person shall knowingly transport or have a loaded firearm in a motor vehicle in such a manner that the firearm is accessible to the operator or any passenger without leaving the vehicle.
(C) No person shall knowingly transport or have a firearm in a motor vehicle, unless the person may lawfully possess that firearm under applicable law of this state or the United States, the firearm is unloaded, and the firearm is carried in one of the following ways:
(1) In a closed package, box, or case;
(2) In a compartment that can be reached only by leaving the vehicle;
(3) In plain sight and secured in a rack or holder made for the purpose;
(4) If the firearm is at least twenty-four inches in overall length as measured from the muzzle to the part of the stock furthest from the muzzle and if the barrel is at least eighteen inches in length, either in plain sight with the action open or the weapon stripped, or, if the firearm is of a type on which the action will not stay open or which cannot easily be stripped, in plain sight.
(K) As used in this section:
(1) “Motor vehicle,” “street,” and “highway” have the same meanings as in section 4511.01 of the Revised Code.
(2) “Occupied structure” has the same meaning as in section 2909.01 of the Revised Code.
(3) “Agriculture” has the same meaning as in section 519.01 of the Revised Code.
(4) “Tenant” has the same meaning as in section 1531.01 of the Revised Code.
(5) “Unloaded” means any of the following:
(a) No ammunition is in the firearm in question,
and no ammunition is loaded into a magazine or speed loader that may be used with the firearm in question and that is located anywhere within the vehicle in question, without regard to where ammunition otherwise is located within the vehicle in question.
(b) With respect to a firearm employing a percussion cap, flintlock, or other obsolete ignition system, when the weapon is uncapped or when the priming charge is removed from the pan.