The topic asks it all, as I noticed the /nvradio/ songs are in /Sounds/ instead of /music/, tho I did drop some MP3s into the /nvradio/ directory but the music did not play..is there anything I am doing wrong?

You can't do it like that, you would have to change the playlist of the according radio station. Ask some of the people who did that in F3 if you want to mod it, or just wait - I'm fairly sure that is one of the few things that can be easily adapted from F3. ^_^

Gotta change the radio station's "quest"/script and you need to have your songs in the exact required audio formats.