Here's a series of pictures showing the repair of a heater box cover broken in the typical area where a passenger's foot breaks them.
A styrofoam block was carved to the basic shape and a layer of clear plastic taped to it to provide a rough form for the fiberglass repair.
Repaired area is primed with DPLF-90 epoxy primer. An off white colored paint is dry brushed in a random pattern to mimic the strands seen in the original material.
A "candy" translucent paint was created by mixing black, orange & clear. This mixture is sprayed over the repair area to blend the color and make the "imitation strands" appear buried. A final coat of satin clear finishes the job.