The foglights on my 91 have an extreme amount of rust on the rear metal portion, where the lightbulb is clipped in. (all the silvery metal that should look silvery is heavily rusted) This was so bad when I changed the bulb a couple years ago I had difficulty removing the clip/bulb at first. Now one light doesn't work and part of the hold down for the clip has broken off due to rust.

I plan on replacing them, but is this normal? Is there anything I can do to keep the replacements from rusting like this? It's the only part on the entire car that has shown any rust and it's odd, considering where they are, that the metal they used would be this rust prone. Kind of looks like some piece of metal you'd find in an abandoned barn that was 50 years old or so. I don't want my replacements to show this kind of rust 10 years down the road, or sooner, so is there anything I can do to the metal?