if you are talkign about the headliner itself, here is a section of the ex headliner i got from the jy yesterday. maybe it will help out.
if you are talking about the metal under the headliner, i started mine at the edge nearest the glass and came back.
here is a pic of my bracket installed. the bracket will look different because i had to cut some off to clear my sunroof. mine may be a little too far forward, i'm not sure. i'll find out soon when i do my headliner.