The standard stereo in my X-Trail is the best audio unit I've ever had in a car. I'm not an audiophile or a boom-car enthusiast (I listen with my ears, not my ass), but I am a serious lover of many kinds of music, and the factory unit does it for me. I have a whole cabinet full of cassettes at home, so I appreciate the deck. The cassette slot also allows my kids to play their iPods with an adaptor, which I can use with my MP3 walkman as well. As for putting an MP3 disc player in the car, I don't know how long the MP3 disc format will be with us, now that you can play downloads without bothering to burn a disc. Maybe it's destined to be the next 8-track.