fyi: to all people in or planning to join the xm nation: for the coming year and years in mobile electronics, XM radio is ABANDONING their partnerships with aftermarket manufacturers IE: sony, alpine, pioneer, etc. . .
what will happen is that each manufacturer will have only ONE or two units that will have XM capability, and they will have the tuner built in such as the new alpine shown in another thread ( nothing extra to purchase except for an antenna) their other models will NOT be designed to use XM. so if you wanna have XM in your aftermarket radio, buy the tuner now while you still can!
there will be only 2 ways you will be able to have XM in the future: MOST new cars will COME with XM allready installed in the factory radio
OR
You can buy an xm tuner IE Delphi SkyFi, Roady, or Commander and have an FM modulator to get sound.
thats it.
it is the goal of XM to get as many people subscribed for as little startup cost as possible. XM wants their product to be accessible to everyone, not just people willing to pay $400 for a head unit, tuner, and antenna. especially when they can sell an all in one tuner for $150.