since I don't see any other replies for you, here is my experience: done by Kingston BMW. about 2500.00 grand total to replace top motor and emergency manual cable and sound insulation etc.
david in Brighton ON
David Bilton, Brighton ON Canada, 2007 Z4 purchased Sep.21/2015 with 18153 KM (11280 miles) in almost New condition. First BMW was 1999 328i convertible from May 2011 to May 2014