Are you planning on filling in the holes for the trunk? Seems like you know what you're doing, hopefully it'll withstand everyday wear and tear. Actually, I had a similar thing done to my car. I don't have the entire rear bumper molded onto the body, but I did get rid of that [vertical] gap under the taillights that are on the very sides of the car (you have the same thing filled in). Good luck with your project.