I bought my Z4 back in January and have been getting familiar with it ever since. I've always kept factory repair manuals for my vehicles, and I wanted to do the same for my 2005 Z4 E85 Roadster. I tried a cheap PDF repair CD, but it was a waste of money.
I found a solid repair manual for my Z4 on my website, which I highly recommend:
https://workshopmanuals.org/product/bmw-z4-e85-e86-2003-2006-workshop-repair-service-manual-download-pdf/