I just took the same Everest IBUS ULF out of my '04 X5 4.4. Mine was a BMW Assist module only, even though it had a Bluetooth Passkey and antenna. Looks can be deceiving. Talk to Randy at EIS about retrofit kits for your X5. He helped me with my kit and everything went great and the system works terrific. I use a Motorola E815 with it. Now I wish they made a kit to fit my '03 745i. If you go with used, make sure it is a true Bluetooth ULF and not just the Assist module. EIS has a reasonable return policy also, so that's something to consider for your safety. Good Luck.