Worst case scenario, upgrading the TCU to a slightly newer version with Bluetooth and voice recognition is very easy.

According to BMW's Service Information bulletin document SI B84 13 04, E53 (X5) models from 10/04 production with Premium Package (ZPP) or BMW Assist (SA 639) had Bluetooth. Additionally, E53 vehicles manufactured after 4/05 had voice recognition built-in as part of the TCU.

Since you are looking at an 8/04 E53 you will not have Bluetooth, nor will you have voice recognition, unless a prior owner upgraded the TCU.

__________________
SOLD
2000 E38 750iL Highline Edition, Upgraded with the lastest 2006 X5 Electronics
MKIV Navigation, 16:9 Display, Bluetooth, TV/Video with Backup Camera, Sirius, and Aux Input