2006 Fleetwood Southwind Stereo Questions

[KY5Q]

Can anyone tell me where the Satellite Radio adapter box and antenna are actually located on the 2006 Fleetwood Southwind? I get a message on the radio that says "Service Sat" and I don't know what that is about.

Alternatively, I am looking at upgrading stereo to a new Pioneer unit with Apple Play and all the bells and whistles. I see that it will require hacking the dash to fit (it is around 1/4 inch taller) and before I take a saw to it, I wanted to see if there are lessons learned.

Thanks
Bill Ripley, Albuquerque