My 06/04 E53 did not come with an ULF, it came with a TCU. Even had a bluetooth symbol and a passkey in the manual and on the module.

However, BMW could never get bluetooth working until late 2004. So my module never worked.

So, i bought a TCU (on ebay) from an early 2005 model and replaced the one in my car with it. Worked like a charm without any software/programming.

BMW Assist does not function, but i never used it also.

BTW, all the hardware needed should already be there , BT antenna, mic etc (except for a TCU with BT).No pairing button needed.