I was incorrect about those buttons, my old 328 had those, my X does not, sorry. What you really need to look for is the 25 pin connector that looks like the connector on a serial cable. This will be present if your X is pre-wired for the OEM phone. I can't dig up a pic right now because the BT section is not up yet. Does that make sense? Any more questions about it?

Where should I look for this 25 pin at?

If you have an 04 - like in your sig you won't have a 25pin connector. I am not sure what you are trying to find but in the back behind that door/flap on the drivers side you will have a 54pin connector with a white lever on it, plus a blue 26pin connector with a plug on it with loops of wires sticking out.

Randy is right, I wasn't even paying attention to your sig to see the year. The BT section is back up, go to article #14.

So all I need is TCU and the eject box? Do I need an extra antenna?

You already have the antenna since you have BMW assist. If you have not already, please read article #14 here: LINK. The kit should also come with the small square BT antenna that mounts on top of the component rack as well. Randy @ EIS may be able to help you with any further questions. He is a preferred vendor here. Just send him a note. His customer service is top notch.

Is this the plug? for a 10/03 build 2004?

No, that's the SES plug where you would connect a voice recognition module. :tsk:

I don't have any other plugs in that area. Is it connected to the ULF module?

The 2004 doesn't have the 25 pin connector. The connector you are looking for is already connected to your Assist module. In order to install Bluetooth you will need to disconnect the Assist module and plug the BT module in its place.