I plan to install XM in my new 3. Unfortunately, I can't use a tape adapter, but I can still use the FM modulator. Even at that, the sound quality isn't that great. I was wondering if there is any way you can utilize the tape/MD button and plug in direct in the back to use as an AUX-IN to get a direct connection, or if there is any other way to plug directly in even without using the FM Modulator. Anyone?