For you that "cultural collossus" only makes itself known when it gets translated into English! :)
Not just English, but in general yes, soft power is based partly on cultural products that are known outside the country of origin - and Germany doesn't have any at present. American over presence is partly to blame but not entirely.
Name a modern German writer as well known as Houllebecq (whose new book won't be available in English for several months) or Ferrante, a modern composer known at all. There is Tom Tykwer (no Herzog, Wenders or Fassbinder but at least competent and fairly well known)
The only German modern author I can think of that people outside of Germany are likely to have heard of is Thilo Sarrazin (and IINM his most famous book has yet to be translated into English)
For the record I have some (mostly passive now) ability in German, I can read genre literature and the popular press without being too reliant on a dictionary and can understand a fair amount of spoken German (as long as its not too dialecty) I'd love for there to be interesting famous German movies and books but... there aren't.
There is a very thriving literature in German, a big movie scene and a very developed art world
Wonderful! But... none of that translates into international soft power (hasn't anyone here heard of hard power and soft power?)
for reference:
en.wikipedia.org/wiki/Soft_power