If you want to have the whole music file playing, the only method available to do this, is actually replacing the original file inside the game directory instead of using this addon. With GCFScape (deprecated, but you can stil use it) or VPKEdit you can "extract" my file inside the mod (a VPK is a container file after all). Mods are installed inside the addon folder in your game directory. The file you want to replace in this case is inside sound/music/tank. After replacing the original file, it's important to use the command snd_rebuildaudiocache! Also, keep in mind that in case of verifying game files because of issues with your game, the original file will actually be redownloaded.