Tip for anyone with a #Citroën XM w/ CD changer: burn discs as Session-At-Once (SAO) to get #gapless playback. This is especially important with albums where tracks blend together. My standard test album for that is Dark Side of the Moon - having two-second pauses between tracks absolutely ruins it.

Having a good source is also important, since MP3s are almost always padded with ~10 ms worth of zero samples at the end due to format specifics. This results in very noticeable clicks between tracks