I've had my 2000 M5 now for a little over 2 weeks. It seems the previous owner set "something" that makes the "ding" go off at h:59. Meaning at 1:59, 2:59, 3:59, 4:59, etc etc. the clock displays in the dashboard with the time and the chime chimes. I've looked everywhere and can't for the life of me figure out where or what this setting is. It's rather annoying...
It has CD-NAV/GPS and DSP sound.