No ... it only terminates to a connector (X14118); doesn't actually connect to the headunit. The fact you have a 2004 would probably mean your car is "AUX input enabled" ie has the cable run ... all you need is the additional cable that connects from the connector (X14118) to the glovebox.
You will still need the cable I mentioned earlier. Once connected you will see AUX option.
Take a look at this
http://www.bmwmotorsports.org/pdf/BM...stallation.pdf
I think it will help. Page 10 for the x5.