Audio Systems: VW Monsoon connecting to Sirius Radio, fm radio reception, vw dealer

Question
I actually got the connector from the VW dealer - not from the parts department but from the sound technician.  Now I don't know into which pins I should put the output of the Sirius turner into the Monsoon-compatible plug.
Any suggestions?  

Answer
it seems there is a specially made interface for this:

http://www.crutchfield.com/S-T3WqavhUarP/cgi-bin/ProdGroup.asp?g=258950

its $130 though!!!! ouch!  believe it or not the FM modulators are incredibly clear.  it doesnt sound like your typical FM radio reception, its 99% as clear as a standard RCA/AUX input on most cars.