This is a complete list of what you need to retrofit a Bluetooth TCU into your ZHP. If you have BMW Assist and want to keep it your car will require coding... if not, then this is all plug and play. If you want voice recognition enabled (for the phonebook only, not navigation) then you need to enable it on the TCU via coding. An Autologic, GT1, ISTA or NavCoder can do this easily. This should run you about $400 in total parts new from the dealer. Also, if you already have BMW Assist, you most likely have a microphone in the car.
Anyhow, the parts list. You need 5 parts:
84316938762 2nd generation microphone
84506928461 Bluetooth antenna
84136912160 Bluetooth antenna bracket
84136924551 TCU Bracket for sedan and coupe (84136924948 for convertible)
84109195455 Remanufactured TCU (latest generation, works with all iPhones, BlackBerrys etc)
Microphone:
http://www.realoem.com/bmw/showparts...84&fg=30&hl=12
Everything else:
http://www.realoem.com/bmw/showparts...84&fg=10&hl=32
Convertible TCU bracket:
http://www.realoem.com/bmw/showparts...84&fg=10&hl=25
Microphone:
Bluetooth antenna:
Bluetooth antenna bracket:
Remanufactured TCU: