When I retrofitted my Bluetooth ULF into my 2001 I installed the antenna in the factory location which is on top of the component stack behind the access panel at the rear on the driver's side (left). There is a threaded post on top of the metal frame and just need to place the antenna on that and secure with a nut. To connect it to the ULF, it required a short cable with FAKRA connectors on each end (purchased through BMW) to be installed and routed from the ULF to the antenna itself.