Does anyone know if the XM radio in the factory head unit is a separate tuner plugged into the head unit. I've had so many billing problems with XM that I would like to switch to SIRIUS. Yeah, I know what your thinking. They're the same right? Well their billing dept is different. So I would like to just remove the XM tuner (if possible) and install a SIRIUS tuner. I don't want to mount a separate tuner on the dash. I want a clean factory look.