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 New Jersey, window tint laws are designed to ensure that drivers have sufficient visibility while operating their vehicles. The state specifies the amount of visible light transmission (VLT) that is permissible for car windows, which is a measure of how much light can pass through the window. New Jersey law requires that the front side windows must allow at least 70% of light to pass through (70% VLT), which means that these windows can have a very light tint but must remain mostly clear. The law is more lenient for the back side windows and rear window, which can have any level of darkness. Reflective or mirrored tints are not allowed on any windows. If a driver is found to have illegal window tint, they may receive a 'fix-it ticket,' which is a correctable violation. The driver must then remove or alter the tint to comply with the law, pay a fine, and have the correction verified by an authorized person, such as a local police officer. Failure to correct the issue can result in additional fines, a mark on the driving record, and potentially a warrant for arrest if court orders are not followed. New Jersey also recognizes medical exemptions for drivers who require darker tints due to medical conditions and have documentation from a licensed medical professional.