Have you ever wondered why tinting the driver's and front passenger side windows is illegal in some states? It usually comes down to a law enforcement safety issue. In many states, tinting these windows--or applying dark tint to them--is illegal, because if you get pulled over, the police want to be able to see into your vehicle. Quite simply, they want to know if you're pulling a gun on them--or trying to hide drugs or alcohol.

To find out what's legal in your state, check out this comprehensive chart, which was compiled by the International Window Film Association.