All states have traffic laws that limit the amount of window tint on motor vehicles—often by specifying the amount of visible light transmission (VLT) that is required. VLT is the amount of light that is transmitted through the window and into the vehicle. For example, a 70%VLT means that 70% of light will pass through the window and 30% will be reflected. Thus, a lower VLT indicates a darker film or tint.

Another term to know is visual light reflection (VLR)—which is the opposite of VLT. VLR is the amount of solar energy that is reflected off the glass and away from the inside of the vehicle.

In most states tickets or citations for illegal window tint are known as fix-it tickets and the ticket or citation will indicate that it is a correctable violation of traffic laws. For example, if you fix the window tint problem within the required period, pay a small fine, and get the signature of an authorized person (a local police officer) the court may dismiss the ticket.

But if you fail to fix the window tint problem within the required period you must pay the fine for the violation and you may be issued another ticket that will be part of your driving record. And if you fail to pay the ticket or appear in court on the hearing date the court may issue a warrant for your arrest.

Window tint laws vary from state to state and some states have exemptions for certain vehicles such as limousines and recognize medical exemptions when the driver has a written statement from a licensed medical doctor, ophthalmologist, or optometrist.

In Missouri, window tint laws are outlined in the state statutes, which specify the amount of visible light transmission (VLT) allowed for vehicle windows. Missouri law requires a minimum VLT of 35% for the front side windows and any level of darkness can be used for the rear side and rear windows, as long as the vehicle has side mirrors. The front windshield may have tinting that allows at least 70% VLT, but only along the top of the windshield. The state also regulates visual light reflection (VLR), allowing no more than 35% reflection for the front side and back side windows. Missouri recognizes medical exemptions for individuals who require a lower VLT due to medical conditions, provided they have documentation from a licensed physician. If a driver is cited for illegal window tint in Missouri, it is typically considered a fix-it ticket, which means the driver can correct the violation and show proof to potentially have the ticket dismissed. Failure to comply with the correction period can result in fines and further citations, which may affect the driver's record. Noncompliance with court orders, such as failing to pay fines or appear in court, can lead to a warrant for the driver's arrest.