It's more to do with the replica's than the wheel cap I would imagine, but my caps are a different part number: 8D0 601 165K.
I just asked for RS4 wheel caps, but this was about 5 years ago. Don't know how different the TT versions are, if at all.
You've probably got the latest ones as 9 spokes are an option on pretty much any of the older Audi's now. When I bought mine they were only available on RS4/TT's