Here is a 2011 Z4 Owner's Manual. Sorry, it for US spec cars. I don't know how to get the UK manual, but I still have a valid account on BMW USA.
https://docs.google.com/open?id=0B7i8NlSm8uFpZjcwOGM2NDYtMmY1MS00MzFkLWE5ZGUtMTY5N2MzMjY5MDNj
https://docs.google.com/open?id=0B7i8NlSm8uFpZjcwOGM2NDYtMmY1MS00MzFkLWE5ZGUtMTY5N2MzMjY5MDNj