My understanding is that that adapter was only for the AM/FM reception. The satellite radio has its own antenna, which is included w/ the satellite module.
I read djczar's post as that he was able to use the stock antenna for the satellite reception as well. If all I need is the antenna adapter that came from crutchfield, then I am set. But, everything that I have read has said that the stock satellite antenna is useless once you go w/ an aftermarket HU. DJ, could you please elaborate a little further. I'm trying to gather all the information that I can before install and my head is about to explode. 
You understood what I meant exactly. Don't believe what people say as the stock VW SAT antenna works perfectly with an aftermarket HU. My main question to you is whether your car already has satellite radio (package 1 or 2) or did not come with it and you have the long beesting antenna on your roof.
If it already came with satellite radio, all u need to do is remove the stock sat tuner box under the front passenger's seat and screw in the aftermarket one to the bracket thats already there. The VW antenna lead will match the connector on the aftermarket tuner box. You might just have to take off the plastic shell around it (usually green in color.) The connectors are called FAKRA SMB.
If your car didn't come with satellite radio however, things are harder but not impossible. You can order an original GTI sat antenna from VW, althought it's quite pricey, a whopping $264. You can follow the instructions here to actually get to the antenna. Although his instructions are for swapping a euro spec am/fm antenna, the dissasembly instructions are exactly the same.
After you put the antenna in place you have 2 options. You can either run custom cable to the tuner box and terminate your own connectors or if you manage to squeeze your tuner box behind the actual HU (like I did with my Sirius module,) u can utilized one of the unused leads originally used for the dual-input VW headunit. Again, pry the plastic FAKRA connectors off to expose the raw SMB ones, and then they just plug in.
Here is a diagram to help you order the parts if you wish.

Hope this helped and good luck!