GT Cyclery

I can not for the life of me get this back glass shrunk properly.  It is my first back glass but I've watched almost every video possible and working with every technique I've read about and viewed. I've tried it countless times over the last month or so and gone through over 100ft of global qdp trying to get it shrunk. I just can not seem to conquer the excess in the corners.  Any advice is much appreciated. 

I've been working outward (toward top and bottom) as evenly as possible with no luck. Should I try to get the four corners seated and then work the middle?

I've been trying to tint the back glass on my forester.  It is the first car I've tinted. Side windows look great but I'm having a lot of trouble shrinking the back glass. I'm using Global qdp and dry shrinking with the H pattern. The center shrinks great but I end up with crumple up corners that can't shrink any further and end up creasing the film. Any tips or guidance is much appreciated. Thanks in advance.

Much appreciated. 

Thank you. I appreciate the lead. How are you sure that this is indeed global film? The website appears to provide no info on the brand.

I'm trying to master tinting for my own personal vehicles and projects. I'm struggling to find quality films for purchase being that I'm not a commercial business / dealer. Specifically looking for websites where I can buy Xpel, 3m or any other highly recommended brands. Any help is much appreciated.