^^^I think it is the P2 that has that "rust" issue or whatever... I forgot about that. Hasn't happened to me..... but I think that I read that it was on the exterior of the box, like the screws or something.... I also think that the person who reported this lived near the ocean and the possibility of salt in atmosphere or something could have been a possibility of the corrosion.
That thread about the "rust" is somewhere, but I'm not sure where.... might be worth finding and checking if that person had any other issues besides the rust with his deck.