That is a different radio than my 07! I cant tell for sure if the xm module will work. But i'm pretty sure you will need the Crutchfield adapter.
Suggestion:
Open up the plastic door in your trunk. Carefully cut the plastic ties that hold the wires in their place and try to get a snap shot of the leads that would plug into the XM module. You can compare that to the photos of the back of the module that's posted on ebay. Pasted here albeit not that great.
The red and green plugs on the right are the antenna leads. I'm guessing you only have one - hence the need for the adpator.
At worst you would be out the cost of the module. The crutchfeild adpator could always be returned if the set up didn't work.
Having both a xm skyfi 3 in my acura (with the FM transmitter) and thisxm module in the A3,the sound quality difference alone is worth the risk! The sound isCD quality.
Good luck!