Vintage Mustangs might be "old" but they still have their fair share of plastic components in the interior, from consoles, kick panels, and small trim parts to the huge quarter trim and fastback trim parts found in the rear of the interior. Okay, some of these panels were fiberglass in their original form, but they can still be a pain in the spray can when trying to refinish them. Of course, reproductions are made in newer plastics and can be difficult to get proper paint coverage and adhesion too.
While you can order many trim parts today in molded colors, rarer colors aren't reproduced, leaving you with the option of buying a neutral color and then refinishing it to match your interior. Some reproduced parts are available only in black. Lastly, we've seen some trick custom interiors that used stock or restomod parts (speaker kick panels, for example) that had to be refinished in the custom interior color to match.
No matter your reason or need, properly prepping plastic trim parts for refinishing is essential to having a nice, even color and a surface that lasts and doesn't flake, peel, or easily rub off.
National Parts Depot can help you achieve paint perfection with not only their full line of interior paint colors, but they have now added a line of professional level plastic and vinyl prep and cleaning products to their catalog. These prep and cleaning items will help you prepare your plastic and vinyl items to accept the finish color of your choice. The trick, if there really is any, is proper use of these products and following their instructions to the letter.
We had a reproduction '67 Mustang console, which comes assembled and only in black plastic, in need of a correct interior color spray. With a call to NPD to order their plastic prep materials and a can of '66-'67 red interior paint, we were ready to make our new console match the rest of our '67's interior.
With materials under one arm and our console under the other, we dropped everything off at Classic Creations of Central Florida, where Merv Rego adeptly handled our console upgrade. Classic Creations of Central Florida specializes in classic Mustang console restorations and repairs, so we knew we were in good hands.

1 The reproduction console...

1 The reproduction console is shipped in Styrofoam for protection and arrives out of the box fully assembled. If you have a black interior, you can simply bolt the console in (with the appropriate fasteners and mounting hardware), but for other interior colors, this new console will need to be completely disassembled and painted to match.

2 Disassembling the console...

2 Disassembling the console is straight forward...

...requiring basic hand tools...

...requiring basic hand tools like a Phillips screwdriver and nut drivers or 1/4-inch drive sockets.

3 Your goal is to strip the...

3 Your goal is to strip the console down to the bare plastic shell. This goes for an original console as well if you're simply refinishing it or painting a good used console the proper color to match your interior.

4 We ordered what we needed...

4 We ordered what we needed to tackle our console from NPD, including SEM Soap (PN 909-15, $13.85), SEM Plastic & Leather Prep (PN C-CPA, $14.60), and SEM Sand Free plastic adhesion promoter for ABS/PVC Plastics (PN AP-SF, $14.60). NPD also carries SEM products for vinyl prep and adhesion promoter for TPO and EPDM plastics.

5 Starting with the SEM Soap,...

5 Starting with the SEM Soap, clean the plastic using a mild scuff pad. We decided to clean it a second time with a lint free cloth just for extra measure. The SEM Soap leaves no residue and cleans the surface, especially if the plastic was in use and not brand new.

6 Rego grabbed our SEM Plastic...

6 Rego grabbed our SEM Plastic & Leather Prep next. This product is applied in wet coats to lift release agents, wax, grease...

...and other contaminants...

...and other contaminants from the surface where it can be wiped away with another clean lint-free cloth.

7 With the console base cleaned...

7 With the console base cleaned and prepped for paint, Rego moved the console to a work stand in another part of the shop where overspray wouldn’t be an issue.

8 For ABS and PVC-type plastics,...

8 For ABS and PVC-type plastics, such as this reproduction console base, the SEM Sand Free plastic adhesion promoter is the proper prep agent. The adhesion promoter is a clear primer that promotes adhesion by gently softening the top surface of the plastic.

While the plastic is still...

While the plastic is still soft, the color coat is applied, helping to link the color to the plastic surface for strength.

9 NPD's interior paint comes...

9 NPD's interior paint comes in deluxe aerosol cans and mixed with PPG acrylic lacquer paints for an exact match for hard surfaces. If you are painting a flexible surface, such as a vinyl interior trim part, convertible top boot, etc. then NPD recommends their SEM line of paints. For our '67 Mustang's interior, we ordered Dark Red Metallic (AP-5773R, $9.25).

10 While the adhesion promoter...

10 While the adhesion promoter coat is still tacky, Rego starts his first coat of color on the console base. Light applications of color are used to prevent runs and ensure even coverage.

11 Sometimes humidity and...

11 Sometimes humidity and outside temperatures can affect the paint's ability to dry. As you spray each coat of paint, a layer of air is trapped under each coat. If this trapped layer of air has a high moisture content, the paint can "blush" and look cloudy. A good way to prevent this from happening is to use a hair dryer or heat gun to quickly heat the air layer before the paint has a chance to blush.

Spray your next coat of color...

Spray your next coat of color and then pass the heat source over the material to dry the air layer. Caution needs to be exercised to not paint while the heat source is in use, as the paint fumes could enter the device and create an explosion.
There are several types of plastic used in Mustang interiors, both in original and reproduction parts. It's imperative you know which type of plastic you are working with so you can use the proper products to clean, prep, and paint the plastic parts. So how do you know what type of plastic you're working with? You can perform a simple test with acetone, as found in nail polish remover. Place a little of the acetone onto a hidden/inconspicuous section of the plastic you are working with (just a drop or two) and use your finger to rub the acetone into the plastic surface. If the plastic melts/smears with your finger, it is ABS or PVC plastic (like the plastic model kits you used to build as a kid). If the plastic is not affected by the acetone, then the plastic in question is a thermoplastic, such as TPO or EPDM. Now you'll know which prep products to use with the plastic you're refinishing.

12 We sprayed four or five...

12 We sprayed four or five coats of color to get nice, even coverage and to ensure screw holes and other small hard to paint areas were completely covered. Once sufficient time was given to allow the paint to dry (about an hour), the console was reassembled.

13 The console is all back...

13 The console is all back together, color matched to our interior, and ready for installation in our '67 GTA fastback.