Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. WAter-repellent glass (WRG) is a chemical film that is baked into the factory-fitted glass on the front, rear, and side windows of a vehicle to maintain proper visibility in wet weather. IT is produced and patented by Volvo Cars. WRG Claims to take water in the form of rain, mud, snow, sleet, or ice, and disperse it into tiny droplets that quickly slide off the windows of the car. THis feature is indicated on the bottom of the glass by use of a water droplet icon near the laminated company name. THe WRG chemical must be replaced on the vehicle after every six years.