By this time in your car's life, you've probably noticed some sun damage on your interior's plastic parts, or some general discoloration of the interior plastics. Short of replacing every single panel in your car with those from a donor car (and hoping everything matches in the process), there is a simple and effective way to spruce up or change your interior color completely, and that is by using interior paint.
From the factory, almost all of your plastic interior panels are molded in a particular, consistent color. When scratched the color still shows through. This is a big advantage for durability and longevity. But you will need to use a quality interior paint to recover those panels. Some of the paints will even work on fabric (check with the manufacturer to confirm).
Before diving into this subject we must be brutally honest about interior paints. They work well...if the part is not in a high-use area. Sill plates and kick panels are constantly getting punished by shoes and as a result, they may need touched up every year. While not a major issue, it still is something that you need to realize. Remember that the paint simply sits on top of the stock panel; the color underneath is different from the top color in most cases. So a scratch or nick will show another color beneath it. There is no way to eliminate this so you will have to learn to just live with it. Always get more paint than you need for just these instances.
There are several different types of interior paint/dye on the market today:
Left: Interior lacquer spray paint has come a long way in recent years, and we're really happy with the paint made by Colorbond. What makes it different is the company's claim that it bonds at the molecular level, hence the name. We found some online and after receiving some test cans of various colors, the first thing we painted was a Cougar 2-spoke sport steering wheel center. After the paint cured for a day, we attempted to scratch it off with keys—and the paint stayed put. Then we painted the entire steering wheel—normally a preposterous idea, due to the high usage of the wheel—and never once has any paint flaked off in our hands. In fact the Colorbond paint has held up extremely well in over 10 years of use. It works really well on all interior parts, like armrests, door pull straps, etc. as well as hard plastic surfaces. We can definitely recommend it, especially if you're doing a complete color change. They also offer some extreme colors, as well as carpet dyes.
Left: SEM offers interior trim paint at automotive paint stores or online. It is not cheap paint but is of very high quality. They offer a myriad interior shades, which is a big plus if you're trying to match the stock color or maybe a sample of new seat material. In the last decade we've used plenty of SEM paints and can report that they truly do withstand the test of time. This paint is true lacquer, which means that the paint will be flexible and that drying time is very fast. We've used plenty of SEM paint on exterior surfaces and it's never disappointed us. Recently they expanded their interior paint line and it should definitely be near or at the top of your supply list for interior refinishing.
Left: Factory-style restoration paint can be found from companies such as Latemodel Restoration Supply. The cans are fairly inexpensive and best of all, they carry a decent amount of all the factory colors used in Fox Cougars and Thunderbirds, plus other Mustang-style colors that we never had. Paint quality is very high.
Factory colors for our cars:
1983-86 Canyon Red — Vinyl: MET-FV14 / Lacquer: MET-FL14
1987-88 Scarlet Red — Vinyl: MET-FV23 / Lacquer: MET-FL23
1983-85 Charcoal Grey — Vinyl: MET-FV19 / Lacquer: MET-FL19
1986-88 Smoke Grey — Vinyl: MET-FV24 / Lacquer: MET-FL24
1985-86 Regatta Blue — Vinyl: MET-FV37 / Lacquer: MET-FL37
One note of caution: some of the colors are not exact matches, despite having the correct name and/or factory color code. If you're just touching up a few panels, this might be a deal breaker. But if you're redoing the entire interior, then this is good quality paint and would do the job quite well. We'd suggest buying one can and testing it out to make sure it's a close enough match to your car's color.
Left: Another offering is interior lacquer from Duplicolor. They have a wide range of colors and several viewers have reported that it looks great and holds up well. We haven't tried any color matching with this brand yet but expect quality to be good. Duplicolor also offers fabric and carpeting paint as well.
Left: Automotive interior lacquer can be mixed up by your local auto paint store. Common name brands are PPG and DuPont. You will need your car's interior code from the door tag for the paint shop to match up that code to a year and color, then mix up however much you need. Even if you can't get the code they have huge paint chip books that feature interior color samples. You can browse to your heart's content and pick out that perfect color. Now keep in mind that auto interior lacquer is usually sprayed with a spray gun, and pints and quarts that need thinned or activated are the norm in this realm. It's also become quite expensive in recent years. If that's out of your league, some shops offer to put mixed-up paint into a spray can for you at a relatively inexpensive price. That would be the way to go, especially if touch-ups are ever needed. We have used plenty of PPG interior lacquer before and it works very well. Pricing depends on the color and what goes into making it.
Before you go spraying away, you do have to know about prepping the panels first. Most hard plastic panels are ABS plastic, and all feature a grain embedded into the panel. If your panels have a lot of nicks or scratches, you'll have to fill those in first or they'll show. Body filler is commonly used; however, a smooth spot in the middle of a textured panel looks pretty noticeable. A simple vinyl repair kit usually has grain samples that you can press into the still-wet body filler to simulate the grain; even if the match isn't perfect it's better than nothing. Sometimes it's easier just getting a better panel from the salvage yard or via eBay. Your call there. Rubbery parts that have broken or are torn can sometimes be fixed by the same aforementioned vinyl repair kits. Again, it may be easier to start with a better replacement panel.
Once you've got all the panels removed, you will need to knock down the shine a bit in order for the paint to stick. Using 600-grit sandpaper or a red Scotch-Brite pad, gently sand all panels (wet or dry, whichever is more comfortable to you). Remember to sand in just one direction; overlapped directions will show through and look bad. Once you're done sanding, clean all panels with a quality degreaser. Everything must be very clean in order for the paint to stick. Once dry, you're almost ready to spray.
Prior to paint we'd highly recommend using an adhesion promoter on the panels. This is a clear substance in a spray can, and when applied to the plastic, it stays a bit tacky. Basically the adhesion promoter will lessen the resistance between the new paint and the plastic. Some plastics do not hold paint well, like the polypropolene used in your radiator overflow bottle, and can actually resist the paint or make it bubble or "fisheye". This promoter prevents that from happening. Once all panels have the promoter applied, then it's time to spray the color coat.
Several thin coats of paint work best. Do not let the paint get too thick or it will run and give you headaches. Just be patient and make sure that the paint dries enough between coats (also known as a flash time). When you're done painting, let the panels dry at least 24 hours before using them. Usually 48-72 hours are optimal. Top coating is usually not needed.