What is the best way to get rid of it before it gets worst?

I'd like to know as well as mine are starting to show more and more rust. My plan as of right now is to hit it with some type of rust preventer and then go over that with black rust proof paint. Does that sound like the right thing to do?

You need to get rid of the rust before you cover it up or its just going to keep getting worse, only hidden under sealant this time. There are chemicals that will de-oxidize the iron, but you may still have to sand it down if the rust isn't all on the surface (eg: some under the paint).

where are you talking about? mine has a black plastic shield

If it's body paint, sand prime and paint. If it's any other part my favorite is Por-15. No sanding required just knock the big flaky stuff off.

My car has ZERO rust since I brought it to Oregon. I'm dreading going back on salted roads. The cars look so much nicer out here.

depending on where the rust is i would highly recomend POR 15 you can get it in other colors as well, but how it works is you scrape off any large chunks and then you clean the area with the provided cleaner then you nutralise the rust so it wont get worse, then you put on the por15 it gets rock hard and it wont chip or flake i have used this stuff before and i HIGHLY recomend there products