sounds like the clips that hold the dash on to the car - might have come off or snapped - have to take the whole dash out to replace them - but before doing that check the following.
Check the side screws on the dash are up tight - can only see these when the doors are open - ends of dashboard.
Check the underneath of the bottom part of the dashboard, that all the screws are up tight - as if not this will let the dash move and thus your issues.
Also look under the dash and see if the air vent piping is connected properly as these someones move around and if not on properly can make noise.
In short - check all screws and clips.
