I ran into the guy that tinted my windows today. So for the heck of it I asked him how he removes the adhesive residue. He said it's a PITA, but he uses a razor blade and scrapes the glue off that way. Not a fun job.
Now on the back window with rear defrost, Do this on a hot sunny day.(I found this interesting) he said that he uses a old piece of the clear backing that window tint comes bonded to. Cuts it to size of the window, sprays down the backing and the window with soapy water. Let it cling to the window surface in which the adhesive is on. No squegee'in. Let it get hot and then periodically try pulling the clear backing off. If the adhesive comes of the window and clings to the clear backing, the glass is hot enough. If not, let it bake in the sun for awhile longer.
So this is from a guy that does it for a living. Whether it's right or wrong, I don't know.
Or he suggested going out to your car at 2 am and throw a rock through the window, and let the insurance company pay for a new window.
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GEN III 5.7L "LS6" Engine swap
TKO500 5 spd.
3.54 Dana 44