1) 2004/08 X3 with Premium Package Assist (TCU 84.116952218)
Bluetooth is not working! However, Bluetooth antenna/Mic Wire is prewired!!!
No need with any KIT, but New TCU and Coding by Dealer
2) Replace Assist/Bluetooth TCU (84 10 6 965 056 - 3rd Generation)
It's very easy, but need to be Code by DEALER. TCU is hide next to the tool box in the trunck. There is a bottom on the driver side in the trunck, and push it. The cover can be remove. It's take 20 mins to take it out and put new one in. It's very simple. After it done, you have to bring it to dealer for coding/software install. It's cost 1 hr installation fee.
3) Assist/Bluetooth TCU (84 10 6 965 056 - 3rd Generation)
It's newest TCU so far! It's with voice command, and it's much easier and safer to dail number while you are driving. I had been blessed to get this TCU on EBAY, and with very very good deal... 3$$. After installed it, My assist got extend almost one more year for free.... I don't know how that happen!!! Maybe, it's another gift from heaven.