CarcentricB

I noticed some corrosion around the oil drain plug of my 2011 CD. See picture.

Is this a known problem? It seems that the black finish was damaged (by previous owner or Porsche mechanic?) and then it started rusting.

Next time I do an oil change I intend to sand the corroded area and then use some Hammerite (or similar) to protect it. Or is there a better solution to this? One of the challenges is that this area is never completely dry. Oil keeps dripping out...
I don't want to replace the complete oil pan since it's quite expensive and is probably not needed.

Thanks!