Time to necro....
So first time it failed, hall sensor replced. 6 weeks later, it failed again, this time part way open, boot open and roof halfway back into it. Back to BMW, said wiring fault. Disputed it was same error code as before, they couldn't argue, got the initial price removed from subsequent quote. Got car back, two scratches on the underside of the roof, back to them to get it to the bodyshop at their expense.
Fast forward 9 months, roof just failed, again, this time in the fully closed position, when I was across the road from BMW. Same error code on dash, same guy at the counter. Not sure who looked happier, me, or him upon seeing me. I know, good specilist indy is best option, but I don't know any down here that will touch it and I am no way capable of doing it myself. At this point as well, should have some kind of warrenty from the last repair