My mom's car has XM; if you have an iPod, it beats satellite radio. (My car has an iPod dock built into the back and an old 4G with a playlist permanently hooked in. I have the 600 best songs in the world....no need for CD's or radio, just one big, LONG playlist of songs I like. And I can skip over songs I'm not in the mood to hear without ever touching the player itself, just through the dials on the stereo.
And it's not headphone, so the battery on the iPod is always charged.