my back windows only roll down using the drivers controls but i can tap the window lock and the person in the back can be holding it down and it will go down a little at a time....

is this a faulty lock or something loose or does anyone know?

My 4.2L A6 is doing the same thing. I have to hold the lock button for them to use their own controls. Anyone?

Yes faulty lock-It comes as one piece with the drivers window switches.