We had Sirius in our 2004 XC90, and my wife liked it. We just upgraded to a 2007 XC90. It did not have Sirius, and the factory Sirius costs around $620 to install. See link:
Therefore, I bought a Sirius Stratus 5 from Best Buy, as well as a hardwire kit and Panavise mount online from TSS satellite. I had a local shop do a custom install. There are no exposed wires, and the sound is great. Since they had the radio guts out, I splurged and had them prewire for a Garmin Nuvi 350 I have. (I had them add another AUX IN plug right below the Emergency Flasher BUtton) I am waiting for another Panavise mount and Garmin-to-four-hole mount to arrive, then I will simply be able to mount and plug in the Garmin next to the Sirius receiver, right above the radio and below the vents.
Once this is done, I will have FM/AM/CD, and Sirius, plus .mp3/audiobook player/voice navigation through stereo from the Garmin, plus iPod if I want with the existing AUX IN plug next to the cupholders. (All for much less than just getting the factory Sirius module installed at the dealer) Let me know if anyone wants pictures of the install. camarkim-at-yahoo-dot-com