Yes the early CDMA ones seem to work. You can fire it up to test it pairs using PWR, GND and iBus. Note it needs IGN and 12V connections.

You will need the 54 pin conector and some pins from Audi.
4E0 972 144 54 pin multilock (Audi) £1.47 - £1.84+VAT
000-979-010 Pins for the connector £0.97 each - £1.28+VAT

Edit: the PWR/GND/iBus are easily available in a handy 2.54mm pitch connector at the CD changer.

If you are intending to build your own cable, then think twice. For a start you'll spend £15 on the BT RF cable, £30 on connectors, and there are a lot of connections to make and most are proprietry and very difficult to locate part numbers. There are twisted paris and shields, and if you want charging the Eject Box needs a loom too. Bite the bullet and get the retrofit cable for ~£80, once the TCU is confirmed working.

I tried to build a cable, bought all the bits, some CAT5e screened cable thinkng I could save money, how hard could making one cable be, with me doing electronics for a living and having access to all the right equipment... Got halfway through it in two weeks. And that's where it stayed.