I suggest looking at the published IR numbers. What most do not understand is that IR from 750 to 2500 nanometers is part of the TSER values. Why? because this near infrared is part of the solar energy.
There is infrared from 2500-5000nm commonly called far infrared and this is more akin to the heat off the pavement or re-radiated heat which as opposed to the solar or a more compressed (shot from a gun) wavelength has less heat energy but is straight up hard to escape even in the shade.
Further, the glass in the car only transmits 20-40% of the near ir. It has mass and a molecular matrix only some of the wave can corkscrew through. The IR absorbing property percentages are less meaningful as a solar filter as a result, because who gives a shit if you are stopping 99 or 97 or 95% of 40 or even 20% transmission. Functionally they are too close to feel a difference.
However, this is not the case for dropping the standing temp inside a car where only IR is trying to leave the automotive greenhouse and 11heat is reflected back inside by the glass. The glass bonded high ir film is the superior method of holding heat to the glass and thus emitting it to the exterior via high emission glass values and convection as a radiator has such a valued effect.
