I have listened to XM in my son's Mazda Protege "listening room" and when simply listening casually, and with routine car background noise, better than AM by a mile, and as enjoyable as any FM in the car that I have heard. The immense variety of music choices avoids any chance of boredom, and there is a limit to how wrapped up in the audio experience one should get when driving. I did not hear any specific recording which I already knew, so there was no absolute reference comparison.
If you simply want to relax and enjoy while driving, there does not seem to be any major flaw.
The moderate cost auto sound system I listened through is not up to home stereo standards, so a "competition quality" auto system may yield a different impression.
If you simply want to relax and enjoy while driving, there does not seem to be any major flaw.
The moderate cost auto sound system I listened through is not up to home stereo standards, so a "competition quality" auto system may yield a different impression.