The reason why the ceiling material in you car might be falling down is because of the age of the material. The ceiling in your automobile is known in the industry as the "headliner". The material that is glue to the board above your head is a double compound textile made of a tissue paper cotton that is bounded to a quarter inch foam.
When the foam ages and start to break down it releases the cotton and enhance you see the material hanging above your head.
The only proper cure is to have the headliner board removed professionally. First step is the professional trades man will take the old material off of the board. Second process will be the thorough cleaning and resurfacing of the board. The third step will be the application of the new material. Fourth and final step will be the re-installation of the board in the automobile.
Can other material be used so that you do not have to revisit this issue ever so often? Yes there are other material that your professional tradesman can introduce you to.
This process should take 2-3 hours on the average automobile however some automobiles with sunroofs can take up to a day. Always make sure you get at least a one year warranty on this job.