Ms. Phyllis Mason
2613 Sunny Meadow
McKinney, TX 75070
Dear Ms. Mason:
This responds to your letter about window screens. You state that you own a vehicle that has a rear window screen that raises and lowers with the touch of a button, and that you find the screen to be very useful. You ask whether a window screen that would operate with a switch built into the car to raise and lower a screen for the front window or windshield would be permitted by the Federal Motor Vehicle Safety Standards (FMVSS). The short answer is that our regulations do not prohibit a vehicle from having such a screen, but we have some safety concerns about such a device.
By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized under 49 U.S.C. Chapter 301 to issue safety standards applicable to new motor vehicles and items of motor vehicle equipment. NHTSA does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, our statute establishes a self-certification process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests vehicles and equipment items for compliance with the standards, and also investigates reports of safety-related defects.
FMVSS No. 205, Glazing materials, includes specifications for minimum levels of light transmittance (70 percent in areas requisite for driving visibility, which includes all windows in passenger cars). Under the standard, no manufacturer or dealer is permitted to install solar films and other sun screen devices in a new vehicle, without certifying that the vehicle continues to be in compliance with the light transmittance and other requirements of the standard.
We have interpreted FMVSS No. 205 not to prohibit a retractable built-in screen for the rear window of vehicles (September 19, 1995 letter to General Motors Corporation). The agency determined in the 1995 letter that the screen is neither glazing in itself nor in combination with the glazing in the vehicle (because it is not attached to the glazing). Similarly, we interpret the standard as not prohibiting a retractable built-in front window screen.
However, we have some safety concerns about in-vehicle front windshield shades. Driving with a lowered shade would be unsafe, as the view through the windshield could be substantially impeded. We are also concerned that these devices could be purposefully or unintentionally deployed while the vehicle is in motion. From this perspective, non-mechanical front windshield shade products that protect the interior while the vehicle is parked do not convey such risk.
Note that States have the authority to regulate the operation and use of vehicles. If you wish to know whether State law permits the installation of front windshield screens in a vehicle, you should contact State officials with your question.
I hope this information is helpful. If you have any further questions, please contact Ms. Dorothy Nakama at this address or at (202) 366-2992.
Stephen P. Wood
Acting Chief Counsel
 Our statute limits the types of modifications that manufacturers, dealers, distributors and repair businesses can make to used vehicles (49 U.S.C. 30122). These entities cannot install a built-in sun screen if doing so would make inoperative any device or design installed in compliance with an applicable FMVSS.