I have a 2009 W212 too... as I said, mine came like that - no bluetooth audio/music - then I enabled it in the engineering menu. Or if you ever take it to Mercedes, they will update the comand software and enable it (they did this for free, in my case, while I had other work done a few years ago).
It seems like you guys found other solutions - for others, see post no.5 in this thread: Bluetooth Audio Streaming
I also added DAB to my W212 using OEM parts (except for the aerial) - it doesn't work amazingly, but it's nice to have.
I'd love to get an Apple CarPlay module working on my NTG4 though, if the prices aren't too crazy.
I've just re-read this properly - If you're right, I could have enabled mine then. I was maybe wrong thinking it was only possible from late 2010 onwards.
Oh well, it's only money.......