Ok.. I actually like the metal music in the game, but not when it's blaring for hours, and you can't turn it down.

Renaming the music directory or removing the files will give you an "insert CD" error, and editing any of the config files seems to do the same.

The music volume adjustment in the game does nothing, and after much searching and trying different things, here's my solution:

This requires no external programs to mute the original files, and it requires no editing of config files.

1: Navigate to your "/steamapps/common/Carmageddon1/CARMA/MUSIC" directory
2: *Move* all the music files to a safe location. (I chose to make a directory called "temp" inside my MUSIC folder.
3: *Copy* the Track09.ogg file back into the MUSIC directory (It's a 4 second long, blank music track)
4: Make 7 copies of the Track09.ogg file
5: Rename them to match the original files. (Track02.ogg to Track08.ogg)

Now you should have 8 copies of the original Track09.ogg, and they should be named 02-09.

Boot up the game and enjoy! If you like, keep winamp running in the background for your own music experience!