I got the upper, rear windshield trim installed today. I trimmed the two end pieces as shown and had no problems. Keeping it in place while installing the glass should be fun. You can see below that that the lower trim now covers the ends.
I asked last night about those rectangular flat nuts for the trim and then realized that Howard provided a few of the sizes on this blog about a year ago. I found what I needed on amazon and saved $20 on shipping as compared to McMasters and Carr.