Back in Dec. of 2004, they quoted me :

* Sirius Tuner/Receiver Module (NAV) #84-11-0-153-365 - $233.75
* Sirius Installation Kit for X5 (E53) #84-11-0-141-976 - $51.00
* Extension Cable #84-11-0-141-977 - $14.66
* CD Changer Cable #84-11-0-141-9781 - $14.66
* Sirius Roof Antenna (Small Style) #84-11-0-390-239 - $45.00