I have a damaged rear spoiler, that I intend to repair. My questions are: What is the material that the spoiler is made of? To me it looks like the "pot metal" of the plastics industry. Do regular fiberglass repair methods yeild good results?
I've used an old soldering iron on that type plastic to "knit" along hairline cracks before laying the fiberglass on. I think it just adds a little internal structural strength to assist keeping the crack from separating. Treat it a little like spot welding and get a good mix of melted plastic from both sides of the crack to form your "puddle". Make sure you don't go too deep or get the area to hot and affect the opposite side.