Vehicle Identification System. Now anyone can permanently etch their federally registered vehicle identification number (or VIN#) on up to six windows of their car, truck or van using our patented Auto Etch System. Each kit contains 6 alignment templates and enough numbers and letters to re-create any number up to 18 digits long. These templates and stencils are specially designed to adhere to glass when rubbed into place. Armour Etch glass etching cream is brushed onto the stencil and after 1 minute, the etching cream and stencil are removed from the glass using a sponge and ordinary tap water. The etched VIN number is permanently etched into the glass."