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+The Music Player Dæmon plays music: http://www.musicpd.org/
+
+The Car2PC interface connects to the head unit in your car and pretends to
+be an CD changer: http://www.car2pc.com/
+
+This small program interfaces between the two, translating the simple
+commands received from the Car2PC interface into MPD commands, and
+returning track metadata to the Car2PC so that it can be displayed (on
+capable head units).
+
+It ships with a sample udev rule which will automatically run the
+mpc-car2pc program when the Car2PC interface appears on the USB bus.
+
+Since it's emulating a CD changer, it supports up to 6 "discs", each
+of which is an MPD stored playlist with the name 'disc1', 'disc2', etc.
+
+Each playlist can have up to 99 tracks. These limits are probably
+specific to the Symphony II head unit in my Audi A3, can can easily be
+changed in the source code.
+
+On starting up, mpc-car2pc will try to work out which disc is playing
+by comparing the named playlists with the current playlist. If none
+match, it will reload disc1.
+
+If you use another MPD client (such as gmpc) to change playlists while
+mpc-car2pc is running, mpc-car2pc will automatically save the changed
+playlist under the name of the currently "active" disc.