I bought one of those kits from Baviarian autowerks.
It was easy to install, i mean litterally took 15 minutes. 5 minutes was hiding the antenna wire to the roof.
Well i didnt have sound at my stereo. I had the signal because the info button would tell me what song was playing on the XM but no sound.
I had dealer install AUX plug for my IPOD so i thought that was the reason why i had no sound.
Finally i get around to calling Bavarian about this and Jason helped me out..
Ended up that i pluged in the blitz box into the CD changer input and the CD changer input behind the radio was not plugged into the radio. I think my Bluetooth was plugged instead. So i simply took the 3 minutes to pull out the radio, found the plug i needed, unpluged the one just like it on the back of my stereo and pluged in the CD one and I HAD SOUND..
This process would of been alot easier if i had time to mess with it, but seriously the install takes 20 minutes and the Xm tuner box from Bavarian is like $300.
I have a pic of the install but dont have it hosted yet. I will tomorrow and post it.