A Matchbox car can take a beating after years of play and storage in (often) dingy attics and basements. If you like to clean up those cars, or even display them, a restoration project will be worth your time. All you need are the proper supplies. You may not be able to perfectly replicate the original, but it's possible to make the cars look like new again.
Drill out the rivets to disassemble the vehicle. Once they are removed, the car will come apart easily.
Soak the car in paint stripper until all the paint is removed. Only the metal frame of the car should remain.
Coat the car with standard primer. Let it dry, then spray the car with spray paint. The colour should be as close a match to the original as possible.
Add any details (such as racing stripes or other detail work) with acrylic paints.
Add a coat of clear gloss to protect the paint job. This is available in both a spray version and a version that can be applied by paintbrush. The spray variety works well since you can cover the entire car without worrying about small, individual sections.
Replace the axels if necessary using 1 ½ inch pins. Cut them down to the appropriate size and stick the wheels back on.
Reassemble the car and dab some glue into the rivets.
As an alternative, use masking tape to cover the areas you don’t want painted with masking tape and spray paint the car in the different colour. But the masking tape doesn’t always give a good solid edge. You can also use a sharpie to add finer details. Add decals if necessary. Wet slide decals, which are intended for model trains, also work well for Matchbox cars. They can be found at most hobby shops.