I can see where you guys are coming from. However, I don't think an APC is going to fix it because to my eyes, it doesn't appear to be white paint transfer. I believe the actual plastic is scuffed, which is why I recommended heat. With that being said, DD makes a valid point as far as brittle plastic goes. Some plastic pieces can't be repaired and should simply be replaced. Specifically, pieces that are under stress should just be replaced. A chin spoiler would be a good example because they're constantly fighting the wind. The piece in question here is located directly above the exhaust and has undoubtedly went through many hot/cold cycles. No longer than the heat would need to be applied to make the repair, it will likely have no seen affect on the brittleness of the piece. My official recommendation would be as follows:
Try an APC just to make sure. If it works, stop. If it doesn't work, you have three choices. Live with the damage, replace the part, or try my torch method.