There seems to be some falsehoods regarding the use of Sun Screening in vehicles.    

A lot of people are under the impression that just because the PA Inspection Stations cannot reject the tinting that it was legal. The fact is even a car that had passed all Inspection Regulations and had a valid sticker could be illegal to operate in PA.

In fact, you will be charge with Title 75 Pa Vehicle Code Chapter 41 - Equipment Standards 

4107 - Unlawful activities.  (b)  Other violations. (2)  Operate, or cause or permit another person to operate, on any highway in this Commonwealth any vehicle or combination which is not equipped as required under this part or under department regulations or when the driver is in violation of department regulations or the vehicle or combination is otherwise in an unsafe condition or in violation of department regulations.

Nature of Offense ? Title 67 - Transportation, Article VII - Vehicle Characteristics,  Chapter 175 - Vehicle Equipment and Inspection, Subchapter O - VEHICLE SUN SCREENING DEVICES,  Section 175.263 Sun screening location - 175.263. Sun screening location.

 (a)  Windshields, side windows and side wings. A person may not operate, on a highway, a motor vehicle with a front windshield, side window or side wing that has been equipped with a sun screening device or other material which does not permit a person to see or view the inside of the vehicle. This subchapter does not prohibit the use of products or materials along the top edge of the windshield if the products or materials are transparent and do not encroach upon the AS-1 portion of the windshield as provided by FMVSS No. 205 and if the devices or materials are not more than 3 inches from the top of the windshield.

 (b)  Rear window. The rear window on a motor vehicle may be treated by the vehicle owner with a sun screening device or other material. If the rear window is treated with a sun screening device or other material, the vehicle shall comply with 175.264 (relating to mirrors). See Table X for specific requirements for vehicles subject to this subchapter.

 (c)  Louvered materials. Louvered materials may not reduce the area of driver visibility below 50% as measured on a horizontal plane.

Pa. Sun screening must conform to the standards of the PA Vehicle Equipment Regulations. The 70% light transmittance standard is measured by police with a light transmittance meter. The windows on most vehicles equipped with air conditioning only allow 77% light transmittance from the factory thereby prohibiting the use of sun screening.

HOW DARK CAN WINDOW TINT BE IN PENNSYLVANIA?

Darkness of tint is measured by Visible Light Transmission percentage (VLT%). In Pennsylvania, this percentage refers to percentage of visible light allowed in through the combination of film and the window.

Windshield	No tint is allowed on the windshield.
Front Side Windows	Must allow more than 70% of light in.
Back Side Windows	Must allow more than 70% of light in.
Back Side Windows	Must allow more than 70% of light in.

       

HOW REFLECTIVE CAN THE TINT BE IN PENNSYLVANIA?

Similar to sunglass lenses, some tinting films contain metallic elements that help in reflecting incoming light and reducing the glare and heat generated by visible light.
 

Front Side Windows	No metallic or mirrored appearance.
Back Side Windows	No metallic or mirrored appearance.

      

OTHER PENNSYLVANIA RULES AND REGULATIONS
 

Restricted Colors	No colors of tint are explicitly banned.
Side Mirrors	Dual side mirrors are required if back window is tinted.
Certificate Requirements	Manufacturers of film do NOT need to certify the film they sell in the state.
Sticker Requirements
Medical Exemption	State allows medical exemptions for special tint. For more details about the specific terms of the exemption, consult your state law.