The color match "problem" at the rear edge of the door to the 1/4 is caused by the metallics and pearls reflecting the light differently since the two panels are at slightly different angles. This is what we in the auto refinishing world call "flop". All the repainting in the world won't cure it, just change it slightly.
I am not sure how the plastic is refinished on the Camaro but most manufactures do it separately due to the high temps used in curing. Some have a better process than others. It can fluctuate from car to car. If you have a bad match at the front facia (bumper cover) to the fenders and hood the only way for a seamless match is to reshoot the cover and blend into the a- joining panels.
Trust me it's what I do for a living.