Once the insulation is installed the next step is to loosely fit the headliner in place.  Start by finding the center from left to right and mark the center on the car.  The front to back position will need to be determined by fitting the material for the rear pillar this may take a while to center properly.  I used a grease pencil to mark the center on the headliner and the car, it wipes off when finished.  Notice the use of spring clips to hold it in place.

Rear First Fitting                Outside Rear First Fitting

Extra Material

You will need to remove some of the access material now so you can start working with the headliner.  Be careful not to remove to much, 4" - 6" access should be about right amount to work with.

Front Clipped & Glued   Rear Clipped & Glued

Now the headliner must be stretched as tight as you can get it then clipped down.  Use rubber cement for the glue, a small bottle is all that you will need.  When gluing the glue needs to be put on both the headliner and the metal of the car.  You must give the glue a few minutes to become tacky before putting the headliner to the metal.  The gluing process should start from the middle and work out to the edges.  You should work in small sections and constantly stretch both directions as you glue.  Then work the opposing side of the car, work back and forth between the front and back, if you do this it will minimize the wrinkles in the headliner.  Place clips on the glued sections as you work to allow it to set well.  Make sure that as you are working you are leaving as few wrinkles as possible.  Glue should only be place on the window frame and no more than 1/2" to the inside on both front and back.

Notice the uneven look around the window area, this is because I glued to far away from the window, keep the glue in the window channel and no more than 1/2" inside.  I thought this would stretch out so I did not fix it, so I have to live with it or remove the window and do it again.

The sides are simply pushed up in the clip, make sure the headliner is tight as you work.  It is best if you start at every seam and make sure it is pulled tight and straight.  If the seam is crooked you will get stress wrinkles which you will not be able to get out until the seam is straight.  You can continue to work the sides until all the wrinkles are out, if you are not in a hurry you can continue to adjust for few days until you are happy with the results.