My wife's old car came with some 35% on the front windows, i loved it.
not factory, but who ever did it did a fantastic job.
i have not had too good of luck doing my own tint.
for some things its ok, but i suspect most of it is the crappy tools i use.
I have a "pre cut" kit for the ol vette, first attempt went poorly.
The cheap tool ended up tearing the tint if i press hard enough to get all of the fluid out, and if i press hard enough to not damage the tint, it looks like ass when it dries.
So the second set of precuts are sitting on the "Vette parts shelf" until i care again.
The heat gun idea would probably work, so far i have just been using the summer sun to fully cure it.
And i have a rattly window on the rear driver side of the hoe, it has been on the list to take it apart to see what's up with it.
usually there is some sort of felt lined adjuster, I'm hoping that's all there is.
I also saw signs that the rear door panel had been removed, and either broke a clip or just didn't put it back together right (gap).
It’s a pain in the ass for sure