I looked up the tint laws for Ohio and this is what I came back with:

You can tint the windshield with any percentage up to five (5) inches from the top edge of the glass, The front and rear side windows and rear window can be tinted with up to 50% tint (50% being the amount of light allowed to pass through the tint.


If you want to do this as cheaply as possible, you can do all the side windows yourself, as they are flat for the most part. Get some cheap tint and try doing it yourself first. The front and rear, I suggest you get a shop to do as with the curved glass, tinting is a real pain-in-the-a$$.