These are the readings I got with the Tint meter (EDTM Digital Power Meter)
Outside Direct sun 254 (high)
Front windshield 95 (no tint)
Side front windows 50 (no tint)
Rear factory tinted windows 15
Roof glass factory dyed or tinted “5”
Rear hatch factory tinted 15
The Y is currently in the shop, getting Crystaline 70 on the front windshield and 35% on the front windows, I think it’s Xpel but will get the correct brand name when I pick it up. Will post new heat rejection numbers when I get it.
This is NOT an accurate way of comparing anything you're having done.
1) The Rear half of the Model Y or the Model X are NOT TINTED. It is COLORED GLASS. It provides glare reduction and privacy. It is not going to block the heat anywhere near as well as the ceramic films will.
2) In order for your "before/after" comparison numbers to be accurate, you will need to take the measurements at the same time of day, position of the vehicle parked in the same spot, with the same outside temperature. Clouds will effect the readings too.
3) The BTU numbers are not easy to translate to real world experiences. A cheap laser thermometer is a better way to understand the changes of surface temperatures. And Finally, a boring $10 porch outdoor thermometer placed on the front seat will give you the cabin air temperatures compare.
4) Having a duplicate car, side by side, at the same time to compare the BTU meter, cabin temperature, and surface temperature readings is a much more relatable way of understanding the efficiency of the film.