Once you retrofit the AUX (pre-wired 3-pin connector is curled up and taped up behind the nav monitor), and have the BT unit plugged into the AUX, you will have to manually switch your INPUT from RADIO/CD/TAPE to AUX, in order to talk on the phone.
The cables in your link will NOT work in your car, you need different part number - there are many threads (i have a thread about the AUX too - I built my own cable from $10 worth of parts -
http://www.xoutpost.com/961741-post33.html) talking about it...
You should check your car for the BT module - go to the trunk, pop the left side cover, you will see the nav computer... in that pocket you should have your amp/DSP unit, a CD changer if you have one, an SES/voice recognition module if you got one, and deep downthere, you might have either a TCU unit (it is the SOS module) or a BT unit... Those two modules look very similar, as a matter of fact, some TCU units WITHOUT the BT ability even sport BT passkey, which totally confuses people... (some people were hoping that either hardware mod or a firmware flash could "activate" hidden BT function, so far I have not heard of any success stories about it)