I have had a great experience with XM radio. I bought a Delphi Roady and installed it in my Pontiac Grand Prix in about 30 minutes.
It will send the audio to my car system two different ways: 1) It will broadcast an FM signal on a frequency unused in my area, or, 2) it has a casette adapter, which is what I used.
I also get to listen to XM radio over the Web anytime I'm near a PC with a broadband connection, and this is a free service to subscribers. That pretty much eliminates the need for an in-home kit.
The Roady is now on sale at XMradio dot com for $49. That's an ouchie for me, I paid $99 for mine three months ago.
Obviously, I don't care for every station available over XM. But there are about 15 that I love, and that's enough to keep me entertained.
If you pull under an awning, such as the drive-thru at your bank, you will lose the satellite signal. Your antenna has to be able to "see" the satelitte in the southern sky, so if you spend a lot of time driving eastbound beside tall trees you'll get signal loss from time to time.
Hope this helps. Good luck.