I use my XM roady through the FM radio in the car. I don't have the unit or the antenna mounted I just toss the antenna on the dash and lay the receiver unit in the seat or console and when I drive a different car it's easy to move. I also realized that the signal will brodcast from the receiver to the FM radio a pretty good distance ( at least across my front yard). It does this well enough that I can place the unit on the dash of my car in the driveway and use an FM radio in the house near a window and tune it to the set XM frequency and it picks up the signal.
Like several others have mentioned since baseball is on XM,sirius was never an option to me. NFL would be nice but thats only one day a week, Nascar I like OK but I don't think I've ever been anywhere that you couldn't pick up the race on at least three different stations with a regular radio anyway. I didn't know that the SEC was on sirius, I was hoping XM would get that.
Basically I listen to only MLB homeplate, the comedy channel 150, Ron and Fex or O & A on 202 and maybe some 80's and 90's country or classic rock. Also of course the Reds and other NL games.