Another option to add Bluetooth for 10/2003 to 03/2005 build X5 is by adding a CPT9000 phone cradle and a BTUM module.

The CPT9000 cradle runs a bit over $100 and the BTUM module is about $200 new on Ebay. You still need the dealer to code the car correctly - see SIB 84 01 03. This is what I did... though I haven't found a good list of phone compatible w/ the BTUM module.

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PORTABLE PHONE CODING PROCEDURE FOR ALL E46 (3 SERIES) FROM 9/03, E83 (X3) FROM 9/03, E85 (Z4) FROM 10/03, AND E53 (X5) FROM 10/03, EQUIPPED WITH THE PREMIUM PACKAGE (ZPP) OR BMW ASSIST (SA639) ALL UP TO 3/05 PRODUCTION

E53 (X5)
The retrofit coding procedure now works properly with the release of DIS CD38 or higher.
1. Select "3 ZCS/FA Coding".
2. Select "8 E53 Series".
3. Select "2 Retrofit".
4. Select "26 Telephone professional US"
5. Continue until coding is complete and new ZCS code is displayed on screen.
6. In some instances an error message "Not possible to retrofit TCU according to coding code" is displayed. If this is the case then manually change the ZCS code according to the attached chart.
7. 2005 MY vehicles have Bluetooth activated from the factory. In order to retrofit a CPT9000 (V60) telephone and deactivate Bluetooth the ZCS code must be changed according to the
attached chart for 2005 Model Year.
8. Turn ignition off for 10 seconds.
9. Install handset and check functionality of the phone.
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2010 X5 3.5d: SOLD, but miss the torque...
2004 X5 4.4i: SOLD, but served us well