So I finally got the thing installed. It's a quality made piece but at least this one was nothing at all like the stock unit in terms of hole locations, etc. Frankly, the factory directions for installing their unit seem optimistic about the ease of the task, too! With the help of a local body shop (who let me help the tech as long as I didn't get in his way) we got it done, but we were really making it up as we went along!
And it still looks lame, but at least the rear window will stay clearer!