BMW Repair: Rear Window wont stay up, 2004 bmw 530i, bmw 530i

Question
Hello, I have a 2004 BMW 530i and the rear window will not stay up.  When I roll the window up and it hit the top it will automatically roll back to half way.  I currently have to touch the button to keep it before hitting the top.

Thanks,

Answer
My guess is it's going up and when it gets closed, it's sensing there is an obstruction, and automatically going down to the 1/2 way point.

Try blocking your other rear window at about 3/4 closed with your hand or a block of wood,and see if it goes back to 1/2.  BE CAREFUL YOU DON'T GET IT PINCHED!!!!

If that's the case, then there is probably a sensor that normally would tell the window that its' all the way up and ignore the backpressure, and that's mispositioned/bad, or the up position is set too high and it gets the rejection that way