I was thinking PAC Audio made one, but not for your vehicle.
Im just curious on what your ultimate goal is for your stereo. More music without having to swap CD's?
I am going off of the assumption that you have some sort of portable music player.
An idea would be to add a product like this (for any mp3 player) http://www.pac-audio.com/productDeta...&CategoryID=45
or this one (specific to iPod/phone) http://www.pac-audio.com/productDeta...&CategoryID=36
If you have any kind of MP3 player you can run it through these. It works of the the Principal of an FM modulator except this taps into your radio antenna. This increases the quality of the sound/signal.
I have also head of people telling Sirius that are over priced and they will not pay the normal fees. Some people have gotten it reduced over the phone. Others have waited for the renewal notices to show up in the mail. Once you are expired they will send notices with lower prices.
Hope this helps you out.