09 Prius #2 XM/Sirius radio install

I've had my Prius for exactly one week and I love it. But I really want satellite radio in it and apparently #2 is not "satellite" compatible". Does this mean I cannot exchange the current in-car radio with a satellite radio (I know I would have to purchase one!)? My saleman at the showroom was good and is trying to find out definitely from 'someone', but I think he's not having much luck. I've scanned the audio forum here and don't understand all the technical language and alphabet. Does someone know what I could tell my salesman to make his life easier?