hi everyone, ive got a 2004 3.0 Z4 and about a week ago my roof decided to die a slow death. ive done hours of browsing the problem and have come to the conclusion that the motor has gone. the symptoms are the roof becoming slower and slower opening and closing which got to the point of it only disengaging from the windscreen and not moving any further. i was considering doing to the repair myslef from a resentment of paying BMW hourly rates but was wondering has anyone had an independant garage carry out the repair and at what cost? Also im struggling to find a supplir for tha part, is it only BMW who produce and sell the part?