Stock Xm radio fades in and out as if it has a bad line of sight to the satellite, obstruction to the antenna etc. The message being displayed is "Loading", if it was the antenna it would be "antenna". Note this is not the notorious xm signal satellite mishap, it started before this, and continues after XM/ Sirius resolved the issue. Hopefully some one has incountered this problem as well. PS does anybody know if the antenna goes to a converter before the stock radio, or does it go directly to the radio?