usually a whining that goes away when the clutch is depressed is indicative of a bad throwout bearing, but thats how it is on mustangs, it could be different on rexes, I dont know.
Could also mean something else.. just relaying my experience. Throwout bearings go bad left and right on mustangs, and I was getting the whining on my car before I traded it (though it was minimal and I didnt really hear it in gear. but I definitely heard it in neutral and it did go away when I pushed in the clutch).