What takes the idea a step further is touch controls and adjustability. The patent drawing illustrates how a passenger could decide how much of the window needs shading by simply dragging a finger along the glass to the desired point. This would be very useful on any side window in the car to give passengers, and even the driver, some shielding from the sun when not driving straight into it. The one downside we can see is the accumulation of finger prints and smudges on the interior glass (which would be especially bad on the windshield). But the benefits could outweigh that annoyance. Or perhaps this would be a good feature to use gesture controls on.