Solar energy reaching the glass arrives as visible light, ultraviolet and infrared, and infrared is the invisible part that does much of the heating you feel in a sunlit cabin. Kepler's nano-ceramic films are engineered to act on solar heat at the glass, so less of that energy is transferred into the interior. Because the technology is built into the film rather than achieved by darkness alone, a lighter shade can still be a serious choice for a Tesla with a lot of glass. What you notice in practice depends on the film range, the shade and the glazing already fitted to your car, which is why comparing the data for the exact film and shade matters. An installer can walk you through the specifications for the options that suit your vehicle.