Sl8tr

hello, I just bought a used 2007 525i and would like to add the Sirius adapter to run through the idrive. I checked my VIN online and I know that my car is prewired for it and that the sirius antenna has the single plug in the truck. I can't figure out the part number I need in order to buy a used one.. There seem to be so many variations that I am worried I will buy the wrong one.

So, what is the correct part # for my car?

Thanks for helping.