There is a new 17 page German spec brochure (in English) downloadable from:
http://www.bmw.com/com/en/index_narrowband.html
Select 3 Series, then Sedan. Click on "All the facts", then "Catalogue and downloads".
From there, you can download a 17 page "catalogue" (brochure) that is similar to the other full BMW brochures. The file is big - about 4MB.