Be sure to have your weapon "In plain sight" while holstered on your body in the car. OC is REQUIRED in the car, unless you lock it in your glovebox, which you stated is not an option, or in separate container not accesable to you, which renders it useless. This crazy law gives you another answer for "why do you open carry?". "Because I am required to open carry while driving, and not required to cover it up when I exit my vehicle". (Although "because I am from Virginia" would be fun to use). There is great info at http://www.ohioccw.org.
Remember, if they serve alcohol, you must disarm in Ohio.
Also must inform officer if carrying.
Are you going to Columbus? I know they have some strange California type anti-2a laws there. Not sure what they are. I just stay away from there.