I am planning on installing XM radio and need to
get access to the rear of the radio so I can plug in the antenna
to the xm converter. Has anyone done this?

 

The radio is held in by clips.You need 2 special keys that slide into the face of the radio and release the clips.The radio then slides out.Radio install places and the dealer have these keys.You can also find them online.The germans use a small antenna cable so you might need an adapter.