Thanks everyone for your interest in this question and shout-out to Landon for putting that diagram together.
Having a lot of back-up breakaway windows is more of a safety net in case the sugar glass breaks while I'm pulling it from out of the mold. I'm no Stanley Kubrick. And it isn't a concern to me if its realistic for a man to punch through a car window. It's more to dramatize the emotions of the story.
To give you a visual of what I'm working with, here's a video showing what I did and how it looks: https://youtu.be/N_yBCDmn4ak.
In this vid, I used saran wrap covered in oil, but the hot sugar glass got underneath some of it, which is why the final frame isn't so great. Tin foil gets too crumbly and the glass gets a jagged appearance. I have also tried using silicone mold, but I left the sugar glass out for 72 hours and melted on me so I will need to retest.
I am getting a lot of thoughts on reasons not to create a breakaway window, but I didn't ask if I should or should not do it. I'm asking for alternatives to using sugar glass and also a better way to make a durable mold of my window. So appreciate your thoughts and for helping me out on my low-budget project. Thanks!