Unfortunately, the voices are in that music. I extracted it from steam file, but nothing can be done. However, I could send you other tracks if you'd wanted so you could use it with your prefered theme menu.
There is a music folder in documents and settings\...\race07\user data\music. I've never tried it.
There is "GTR Evolution NO Intro Screens for Steam" on nogripracing.com in race 07/gtr evo/race on > misc files & patches section. But the files are just plain video files so you can use it also on Race On. Add its content to your race07 according to intall txt file. Then simply copy on of those files and rename it to "RACEOn_Intro.bik". It works. But still, it's not straight to the menu and you have to press space bar on time.