Go to the Viastech web site ( www.vaistech) Then have the modules you need and can give you good instructions on installing it if you want to. I strongly recommend sirius over xm. I get real tired of the commercials and verbal commentary on XM.
The sound quality of the Viastech modules with your Levinson system will be INCREDIBLE since you are putting a digital signal directly in to a digital system. When you get done with the installation, it will look just like it did when you drove it out of the dealership.
Good Luck!
If you're concerned as I was about installing a kit yourself locate the nearest Tweeters (tweeters.com to locate nearest to you). They will sell & install the kit. They told me only XM would work, but I was only the 3rd one to buy a kit at their florida stores
The cost for the converter was 325. Install and the XM receiver & antenna came to another 125.
Like everyone else said, hit the am button twice. The audio is awesome. :D