This factory photo depicts...
This factory photo depicts a 1991 Formula when new. None of these cars is new anymore, hence this story.
Part I discussed the cures for chronic Third-Gen. overheating, non-working headlight motors and busted hatch latches. In Part II, we will continue our diagnosis and recommended cures with an examination of the headliner, because every time I get into the GTA my head is accosted by the sagging headliner. It is not only annoying but it looks horrible from inside and out. Of course it's a common problem with Third-Gen. Firebirds so I decided to save a few bucks and fix mine myself.
First, pull out all the interior panels that surround the headliner. Most are held in by Phillips screws (speaker covers and sail panels) or by "Christmas tree" fasteners (trim pieces above and in front of the doors). If they are the Christmas tree types, you just grab the part and pull until it comes off, which can often mangle the fastener. Our friends at Ames Performance Engineering sell these precious items for about .25/each, so yank away.
Once you have removed the trim pieces, the headliner is held in by the dome light body, the sun visors and four clips between the sun visors. Squeeze the dome light lens together side to side, and it will pop out. Remove the bulb from the dome light. There are two star washers on studs holding the dome light body in place. Push up on the dome light body and use a small screwdriver to work these loose. Remove only one; you will need the dome light to support the headliner while you are taking off the sun visors. There are three screws each, and the sun visor mounting bosses often stick firmly to the headliner so be careful not to rip the headliner backing when you remove them.
Now, you will need to remove the bezels around the seatbelt holes, and work the seatbelts out of the slot in the headliner. At this point, open the rear hatch and get someone to help you. Remove the last star washer from the dome light body. The electrical portion of the dome light will stay in the roof, but the headliner will now drop down.
To disengage the clips just behind the windshield, you need to shift the entire headliner straight toward the passenger door. You will also probably have to gently peel away parts of the assembly from the sheetmetal roof of the car since they have become quite friendly over the years. Do not bend your headliner! It's only fiberboard, and bending will create huge creases to repair. Now you and your helper can feed it out the rear hatch.
Next, carefully peel away the old headliner material from its base, as you will need to replace the stock fabric. For some reason, the foam backing on GM material disintegrates over time, and there is simply nothing left to glue to. It's like trying to glue your headliner to the side of a sandcastle. We ordered headliner material from Year One. A can of 3M Trim and Weatherstrip adhesive is another key to a successful job. Now that we have our materials, we must prepare the headliner base. I recommend a heavy steel wool (about $1 at any hardware store) to completely remove all the brown crud that is the disintegrated original lining foam. Do not skip this step, or your new material will come unstuck inside of a week! Next, take a careful look at your headliner base. If there are cracks or divots, first seal and glue them with paper and cardboard craft glue; even white glue works well. This will stabilize the area for repair. Wipe off the excess. When this area has dried, fill all voids and missing areas with silicone and put a piece of paper over the top of the silicone to give a smooth surface. The foam backing on the material will hide a lot of little sins, but not larger divots or cracks.
Wait for this to dry, and find a large flat area where it is okay for a little glue to over spray. Spray your adhesive thoroughly on the backing board and on the foam side of your headliner material. Follow the instructions regarding cure time. Now drop the headliner base onto the glued material and go around the edges and "stick" them. Trim the excess material leaving about one inch to roll over the liner and glue to the top. If you come up short, don't worry; about 3/8 inch will be hidden by the interior trim pieces that cover the edges of the headliner. Now flip it over and you should be able to smoothly stretch and attach all of the material up to the headliner base. Start in the middle near the dome light hole, and work your way out. Don't hurry and wrinkle it or you'll be staring at that wrinkle for the next 10 years. We found a paint roller perfect to smoothly stick the headliner material to the base. Do this thoroughly, but don't put additional cracks in your base by pressing too hard. Let it set overnight, then do it again just before you trim out the holes for the seatbelts (don't forget the slot to get the seatbelts into the holes), dome light and sun visors. I recommend a very sharp X-Acto knife or a razor blade. This material is very stretchy and tough to cut so be careful not to hack your hand off with your sharp toys.
Reverse the method of removal, engaging the clips in front first, then using the dome light body to support the new headliner as you thread the seatbelts back into their holes. Replace all the interior parts in reverse order, and you're done. If you have followed the instructions, your headliner will look like new for years.
 Does this look familiar? ...  Does this look familiar? Like when the stakes pull out of your pup tent ropes ...? |  After removing the rear and...  After removing the rear and side trim pieces and the sun visors, the headliner is held in only by the front clips and the dome light. Push up on the dome light body, and use a pair of dykes to work the star washers off. Keep the rear hatch open and support the headliner when you remove the dome light, as this is the primary support for the headliner base. |  After removing the dome light,...  After removing the dome light, move the whole headliner toward the passenger side of the Bird to release the front clips. Make sure you carefully release the headliner backing if it has stuck to the roof where the sun visors were pressing them together. |
Here is the inside of the... Here is the inside of the headliner trim piece for the A-pillar. "Christmas tree" fasteners are reusable ... sometimes. The only way to remove these trim pieces is to grab them and rip them off, hoping for the best. Each one extends all the way to the seatbelts in one piece, and the overhead fasteners are different, difficult to remove or reuse and no longer available at dealers. Imagine our joy at finding a new set in the bottom of the headliner material box from Year One! |  The new fabric with the foam...  The new fabric with the foam backing intact is in front of the old where the foam has disintegrated and left nothing but crumbling crud on the headliner base and the back of the old fabric. This old foam must be removed or gluing up your new material will be like trying to stick it to sand. |  Steel wool works well to remove...  Steel wool works well to remove the excess rotted foam rubber. Don't use the kind that comes with soap in it. |
 After "sticking" your new...  After "sticking" your new fabric and foam all around the edges of the base, trim the material leaving about an inch all the way around. Spray your glue on this overhang and on the outer inch of the roof side of the base, and roll it over and stick it, too. |  With a clean paint roller...  With a clean paint roller (did I really need to tell you that?), gently roll from the dome light area out to the edges of the headliner. This material is very elastic and forgiving, but be sure and stick it down while not mashing or cracking the rather delicate headliner base. |  This is the base trimmed out...  This is the base trimmed out for the seatbelt holes, dome light and sun visors. With the strong sidelight, you can just make out where the repairs were done underneath with the silicone and paper. These will not be visible when the headliner is installed because there will be no strong sidelight inside the GTA. |
 Install the headliner back...  Install the headliner back through the rear hatch, being careful to thread the seatbelts back into their holes. Fit the front clips (third photo) back into the roof, and put the dome light back in to hold it in place. |  We reused the push (Christmas...  We reused the push (Christmas tree) fasteners with the Year One-supplied bayonet fasteners to replace the window trim. Replace the sun visors, rear trim piece and the speaker covers, and you're finished. |  A taught, non-yellowed or...  A taught, non-yellowed or stained headliner makes a huge difference in the interior, photographed here before the sun visors were installed. |