I had 80% Ceramic (Llumar Air 80) tint put on my windshield when I had my car tinted. Legal in NC and we don't have any stickers on our windshields anymore. It's just to block heat though, not for looks as it's not visibly any darker than no tint at all. 50% is also available but technically is not legal. I believe it was $120.
A coworker of mine just had 50% put on his today but I haven't seen it in person yet due to the hurricane. 50 may be OK but I would think anything darker would be a problem. I'd hate to have to look through my 35% tint at night if it was on my windshield. Might as well drive with sunglasses on.
