I'd say don't scroll at all. It's my car, it's my music, I know what's playing. Cut off the ends of the strings that are too long with '...'. Would be ok for me.
I think it would be more useful if the fields were touchable, ie I can tap on the album/artist name and CFE asks if I'd like to play all the songs from this album/artist or something like that. In that context menu there could also be such a scrollable field like you had in mind.
Btw. I've been busy lately, do you still want the button images I suggested? If so, I will try to make them fit your size requests and send them over. What about the "eject-button-issue"? ;-)