Every Spring I get under my 100 series and get rid of any rust that it picked up over the winter from the super salt the state is now using. I use rustolieum paint to cover any area that the paint is getting thin or has been chipped. By doing this every spring my 100 looks new on the underside and rust never gets a chance to damage my 100. Just a suggestion that if you plan on keeping yours you might want to do the work on the underside.