Whether you love or hate cleaning your car the one thing that infuriates everyone is to see their once shiny, pristine finish covered with watermarks. These marks are caused by limescale in the water and as the final droplets of water evaporate off your car these leave behind this limescale (much like in your kettle) which then 'sticks' to the metallic surfaces of the vehicle. FilterLogic car wash filters are designed to remove the scale forming minerals from the water for the final rinses - No limescale, no water marks!!