mysterious bluetooth setup

[bmwz1111]

So I have had my x5 for 2 weeks now, and everything is going great. As I have been examing the car, I have been seeing tel- tale signs of a bluetooth system, but I am not sure if it actually has one or not. The first sign was a card that came with the owners manual. There is also what appears to be the bluetooth antena in the trunk, and the built in phone dock is missing from the armrest, even though the vin says it should have one.....the cars birthdate is 06 of 2004, so I know it wouldnt have come factory, but the bluetooth passkey card has a 12.06.2004 date on it. Is it possible that when the original owner purchased he had bluetooth installed? and if so how does it work? thanks for any help you can give