Volkswagen Repair: 92 VW Jetta - Gas / Automatic, cv shaft, wheel bearings

Question
My car recently started to make a loud hum sound that changes at different speeds. It causes vibration in trim & roof liner (but not steering wheel or seats) I suspect wheel bearing, transmission, ? Any ideas

Answer
You said it changes with speed, so I am definatly thinking its a rotational vibration.  My first guess would be inner cv joint.  When the outer ones go they click when you turn and accelerate, when the inners go they vibrate at high speeds.  You can check the cv joint by jacking up the car and grasping the cv shaft and give it a good shake, if there is any movement there its gone. You can also check the boots that cover the joint for tears.  Other possibility are the wheel bearings which can be checked by jacking up the car, grabbing the top of the tire and shaking back and forth, again any movement and your bearings should be replaced.  Good Luck and let me know how it goes.
Ryan