I have done it, don't know about any threads, I just pop off the flares, and painted then on the parking lot where I use to live. I have since learned and you might try before you paint that paint solvents will removed the bad plastic and leave you with the original color. I would recommend trying this first, as the fusion will chip around the edges. The taking off and putting back on has caused them to want to fall off now, a few years later, and I am working on that now. The paint solvent will only remove the top layer of rubber and plastic, the layer that is sun damaged. The fusion will have the same problem after a few years of sun. I will say that the paint solvent should be ok as the modern clear coat if very strong and many layers. I learned about this idea for fixing window seals and plastics from my wifes cousin who owns a body shop.