GREENSBORO, NC -- This window tint, it's from the factory.

But if you wanted to tint the other windows, not from the manufacturer, you'd have to get the tint inspected and that will cost you $10.

North Carolina has rules: The tint can't extend down more than 5 inches on the windshield and it can't be darker than 32%.

In fact, you can get a ticket. A viewer named Chris wrote us saying, "I recently got pulled over and received a ticket for window tint violations. My windows are darker than 35%. But I constantly see police driving around with blacked out windows. I would love to know how the police can break a law and yet ticket me for it."

Here's the thing, the cops aren't breaking the law. The Department of Transportation pointed me to this state statute: G.S.20-127 (c) (8).

Under C are all the tinting exceptions, including motor homes, ambulances, limos and yes, law enforcement vehicles. What's really interesting about this is not all law enforcement vehicles have the dark tint. I talked to Greensboro police and found out patrol cruisers don't have tint-- the windows are clear. But specialized vehicles like for undercover, detectives, K-9's have the darker tint.