There isn't a direct download of the Carm2 OST due to licensing issues, but it appears you can grab the tracks from the installation folder.

"You can nab the OGGs out of the directory though, which is as good as really."

http://www.gog.com/forum/general/release_carmageddon_2_carpocalypse_now/post60

http://www.gog.com/forum/general/release_carmageddon_2_carpocalypse_now/post47

Have GOG done anything to make it play the ogg files then or do they play natively?

Only I have Carmageddon 2 on my machine that took me quite some time to get it working. I had to use nGlide and then find some unofficial fix to allow the menus to work at resolutions greater than 640x480 (without the fix the mouse could only move in the corner 640x480 area making many of the menu buttons unusable). The only thing I couldn't get working was the music.

@korell: GOG indeed hacked the executable very nicely to allow music playback again (it was disabled in C2 latest patch).

Suppose that means it is incompatible with the unofficial Super Patch v2.0 that I used to make mine work with resolutions greater than 640x480. So, did GOG fix that problem as well?

Korell: GOG based their version on the V2 patch so yes that mouse-in-the-box issue won't happen either. One could see their executable as a V3, IMO :)