Solar energy reaching your Tesla arrives as visible light, ultraviolet and infrared, and a film has to deal with all three to make a real difference inside the cabin. Infrared is the invisible portion that does much of the warming, and it is what the nano-ceramic layers in Kepler’s IR and IR+ films are built to target. Visible light is handled by the shade you choose, and UV is blocked to help protect seats, trim and screens from fading. Because the heat work happens in the ceramic layers rather than through sheer darkness, a lighter shade can still be a serious performer on a Monroe summer afternoon. Compare the published figures for the exact film and shade before deciding, and talk the choice through with the dealer handling your enquiry.