Here is a picture of my XM Commander Unit installed in my 2004 Boxster with the Hi Fi Sound Option and the MOST fiber optic radio.
This is an interior shot. If you look closely, to the left of the interior sensor on the top of the dash sits the antenna.
The Controller is mounted where the upper storage bin used to be.
It is just the right height to be out of the way of the shifter.
Dave
E-mail me if you need specific instructions.
DDAllenDesign@aol.com