They never put them standard in cars and mp3 players made the max carry around size smaller than a disc walkman. Nobody will carry around something that big for music anymore. It would be like carrying one of the brick cell phones. Bands like the Flaming Lips have come out with DVD audio discs though. It over complicates it though, using 5.1. Stereo is king for music unless you're going on a psychedelic experience or something.