Nice try Sam,
Did you really expect BMW to make your life that easy..lol
I know we've pm exchanged on related matters, but for others reading they will need the Bimmernav kit, although you could source the harness yourself as part # 61 120 154 335. You'll also need a slew of bits inc. mike, bluetooth antenna, mike extension lead, bluetooth aerial and if you go for the built in then add to that the new flap and cradle, more harnesses and/or a pairing button assembly.
I went for the later column mounted mike and had to make my own adapter and Bimmernav forget to tell you about £50 of new carpets to cover the ULF and carrier!!
Big big big retrofit job, but oh so cool once done.