I may be wrong, but I think you cannot use such a telephone unit as a bluetooth phone in your car... that's NOT a ULF.

I have one of those in my car (see this thread) and I'm seeking advice as it doesn't work anymore, so I already investigated several options.

Hope my experience will help you...

BMW TCU can ONLY communicate with its handset, NOT with other phones.
You got this ...and you need these other pieces to get it to work..!

I don't know if you can mix pieces (TCU from a car and handset from another one)... but you CANNOT make it pair with other phones.

BTW, I had the same problem when using Navcoder (cannot write on TCU, just read from it) and I thought it was because there was no need to activate bluetooth not there is a way to change its name and PK.
Correct me if I'm wrong (I was about to pm Jochen about this matter myself, then I thought that was the reason).

Hope this helps.