So I dropped the car off and the installer came out to do a walk around and asked me about doing the cut out. He mentioned it was totally possible and he has done it in several cars, but doesn't recommend it. He said the eye is instantly drawn to it and no mater how good the overlap is there will always be light bleed around it. Every time he did it for someone, within a max of two days they were back having the window redone. So It looks like I'll go with the 4th break light and maybe even wire in the
this to it just to make it a little more visible.
Thanks to everyone for your input. I'll update the first post with pics once I get her back.