Tinting the windows of one’s vehicle can keep temperatures down inside the vehicle, but it’s important to keep in mind the regulations that go alongside the procedure. Missouri law states the front driver and front passenger windows can be tinted to allow just 35 percent of light through the window with a variance of 3 percent when checked. A window that reads less than 32 percent can be cited and carries safety risks, as it deteriorates the peripheral and rear field of vision of the vehicle operator. The front windshield is also subject to regulations, which state that no tint should be applied to the windshield below the AS-1 line. That line is visible on most windshields and is installed by the manufacturer. A violation of the Missouri tint law carries a $75 fine, plus a $30 administrative fee if the vehicle is registered in Missouri. Out-of-state cars must abide by their own state regulations. There are exemptions to the law, mostly regarding medical conditions such as lupus, sunlight allergies, photosensitivity, and melanoma. More information on Missouri window tinting laws is available on the Missouri State Highway Patrol website.