I've recently got 2004 e53 with known sunroof problem. When inspected closly I found out that motor PN 67616922652 is missing. Don't want to buy from dealer but seen a lot e39 on ebay which do apparently fit X5. Altho different part number 67618377939 I wonder if anybody has tried it. Also, my curtain could move until I've tried to re-initialise the system. Now is an inche open and inoperative. How easy is to access the rear motor to manualy wind it back?

Thanks