This procedure is for 86/87/88GT lenses, but may apply to the standard Fiero tail light lens as well.
Over time, dirt finds it's way inside the Fiero taillights. A simple procedure gets them looking new again.
First remove the taillight assemblies by popping off the six black caps located just inside the trunk, above the lenses. Remove the six phillips headed screws, and the lenses are now loose. Remove the light bulb sockets by squeezing the locking tab, and twist one quarter turn, then lift. The small bulbs for illuminating the "PONTIAC" name have no locking tabs, so just twist and pull. The lenses are now removed.
Identify the six plastic locking tabs on the back side of the lens. Carefully pull the back half of the lens from the front half. When the locking tabs get in the way, pull the tab hoop from the latch. Working this carefully, the lens comes apart. There are four main pieces of a lens... the plexiglass window, the light bulb reflector, the red and yellow reflector, and the red "PONTIAC" filter.
Remove all the black sticky sealer by getting a ball of it in hand, and press it into the remainder stuck on the pieces. Work it in, and pull away. The stuff in hand latches on to the stuff stuck to the plastic, and then pulls it off.
After the lens parts are free of black sealer, wash them with soap and water. Get all the scratches off the plexiglass window with scratch remover. Then polish and wax both sides of it.
Buy a tube of clear silicone rubber for outdoor use. GE makes a good type for about $6.00. This tube is used with a cheap caulking gun, that costs $3.00 to $5.00. You will need that much sealer.
When all the parts are clean and dry, and the lenses are polished and waxed, apply the sealer to the trough of the light bulb reflector piece. Apply a VERY LARGE bead all around the trough with NO voids. Then immediately reassemble the unit before the caulk starts to set. The seal will be perfect. Let excess caulk ooze out. Do not try to rework it. Just let it cure for a day or two.
Each light bulb socket has a black spongy doughnut seal. Remove the seals and wash them with soap and hot water. The hot water will swell them up, to improve the sealing action. Let them dry overnight. Check all the light bulbs for functionality. Any blackened bulbs should be replaced even though they still work, because they will soon burn out. Reassemble the lens to the car, and they'll look great for years.
From: Ron Dittmer
"How do you get the things apart? I see all of the tabs that interlock to hold the assembly together...and I've gotten them all unfastened, but the taillight doesn't seem to want to come apart. I notice that they seem to have a sealant all the way around the base of the assembly where the lens contacts the base."
Use a utility knife to separate the two pieces. Once you get it started, the sealant will (or should) pull away easily. Use a silicon based sealant from any hardware store to re seal them.
From: Hal Spalter
"I was wondering if there was anything that I could put on the clear lenses of the tail lamps so that the UV rays won't get to them and make them opaque and whitish looking? Is there any way of taking the little fine scratches on the lens disappear?"Well - if they are REALLY bad and deep the first thing you need to do is WET sand them with 1000 grit sand paper, follow with 2000 grit. When you finish, the lens will be dull and full of very tiny sandpaper scratches. Using a FOAM polishing pad in an electric drill follow up with some WHITE polishing compound. Rinse the pad well and buff again with either a plastic/fiberglass scratch remover or Crest with Baking Soda toothpaste. If you still do not have a good high gloss you can put several coats of FUTURE acrylic floor wax on the lens with a foam pad. (This can be removed with ammonia) DO NOT spray the lens with a clear coat as many of these will actually disolve the plastic!
From: Randy T. Agee
Toothpaste works great for plastic and plexiglass scratches. Use it like a polishing compound.
From: HardRocker
Also Meguires makes Clear Plastic Cleaner (#17) and Clear Plastic Polish (#10). Sandpaper first. Super fine steel wool with the plastic cleaner and then cloth with the plastic polish. I have done this may time wiht the stuff I have and it works really well. Meguiars can be reached at (800)-347-5700
BTW I just polished my stock exhaust tips and it only took 20 minutes they looked like they had never been polished before, but now they look geat!! I used a polish call Simichrome Polish. It says on the side that it is manufactured in Germany and imported by Competition Chemicals, Inc. Iowa Falls, Iowa 50126 Don't let the name fool you, it doesn't work very well on chrome, but anything aluminum or steel, it really kicks but.
From: Greg Pierce