My sympathies if they do. This is a great way
to get dissimilar metal corrosion in your airframe. Over time the metal plugs
(left unpainted) can tend to rust as well. While the Home Depot/Lowes metal
plugs look nice and shiny when new and are quite tempting, many folks suggest
that plastic plugs would be a good alternative.
Just be careful of placing them topside where
they can be exposed to the UV rays of the sun, as many common plastic plugs do
not contain UV stabilizers, they will embrittle and yellow over time. Less of a
factor if your plane is hangared most of the time.