Have my RS4 1 week today and lovin it.

When I select "tel" it asks me to use my mobile phone. Audi tells me today that unless I have a cradle (I don't) then I do not have bluetooth. The previous owner has a flimsy little Nokia thing that I can connect with and still get bluetooth over the speakers etc, but the functionality of my screen is nil.
My brother has a new A6 Le Mans and he can use the Nav Screen to see his numbers, dial number, etc etc. Its a class feature that I like / want.
So, am I stumped? Is there no way I can buy software etc to activate the bluetooth feature of the MMI screen without a cradle?? Am I stuck with the Nokia "kit"?
Any help / advice appreciated.
Thanks
Ronan