To a point.  The statute governing Tinted Car Windows is at M.G.L. ch. 90 § 9D.

Under the statute, you may not tint any of your Car Windows if the tinting results in your windows being nontransparent or obscured from either the inside or the outside of your car.  A conviction carries a $250 fine. A third or subsequent conviction carries a 90 day license suspension.

However, the statute provides several exceptions.  You may use tinting on the Side Windows if the tinting does not reflect more than 35% of Visible Light or if it transmits at least 35% of visible light.  The same percentages apply to the rear window, but only if your car is equipped with an outside mirror on each side that clearly shows your rear view.  It is also acceptable to use any transparent material along the upper 6 inches of the windshield, if the strip does not impede the driver’s forward viewing area.

Vehicles registered outside Massachusetts are exempt.  Vehicles that are registered and hired as public livery vehicles (but not taxicabs) may tint the side windows immediately to the rear of the operator and front passenger seat as well as the rear window.  It is also possible for individuals who are light or photo sensitive to get a medical exemption.