Headlight covers are aftermarket modifications made from a variety of materials (e.g., metal, polycarbonate, ABS plastic or self-adhesive vinyl film) which are applied over the headlamps of a car in order to reduce the percentage of light transmitted, to tint the color of the light transmitted and/or to protect the lenses from stone chips, bug splatters, pedestrians and minor abrasions.
The use of headlight covers and the modification of light produced by vehicles has continued into the present day in both the military's development of special blackout head and tail light technologies and in the civilian sector as well. In addition to headlight covers' use in light reduction, they have also been employed to protect headlamps from damage in both civilian and combat environments. As of 2014, 3M makes a wide variety of aerospace and military films solely for this purpose.
Evolution
Eventually, the automobile industry began to take note of the protective benefits of headlight cover film, and it was soon being employed by race car drivers despite the difficulty of working with the original films. According to Kay Lam, marketing manager for the automotive division of 3M, "The first films were thicker and less compliant, [because] their purpose was to help keep...[surfaces] from eroding in the harsh, sandy environments to which they were exposed."
