X5 Bluetooth Module or Retrofit Kit
 

Hello,
I have a question about what to purchase for my vehicle. I have a 2004 X5 with Assist and bluetooth that BMW never got the Bluetooth working in. I need to add a Bluetooth module but I am trying to figure out if I need the Retrofit Kit or if I just need the TCU. I understand that I will lose the Assist functionality. What does the eject box do for the Bluetooth module?

Thanks!