The head was all rusted up and the dealership must have overtorqued it at my last service, so I ended up stripping the head. However, when I ordered the replacement part, it now has the same magnet that the drain plug does. I asked them if they ordered the wrong part and they weren't sure, so they called in one of the service advisors, who mentioned that they changed the part so that both the fill plug and the drain plug have that magnet.

It's only $5, so something you may want to order to help get better filteration.