take pics.
there two large piece of fabric that rolls out from rear to front to shade the pano roof glass.
if the rear piece isn't coming out, it must have ripped off its guide wires/assembly and you'll need to remove headliner (good luck, not hard just time consuming and a PITA) and remove the cloth thats stuck somewhere. I NEVER have my cloth shade closed (covering up the beautiful glass), so personally if I was in this position, I'd just remove and disguard and never fix the missing cloth shade.

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I swear, my cars are like a girlfriend.
Sometimes its a rough ride, sometimes its smooth motorin'.
Sometimes she doesnt like how i treat her and sometimes i dont like how she behaves.
BUT at the end of the day, she loves it when I am inside her.

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'91 850i
'05 X5 4.4i
'09 Clubman S