My WHITE 06 ML350 has been taking a beating with the winter weather this year. After a wet snowy trip through the iron mining areas last winter, a car wash revealed that many tiny flecks of metal from the road must have stuck to the finish and then rusted and discoloring the clear coat - many tiny rust colored spots on my white paint. I was able to remove them mostly. However this winter I am finding this to be an even larger issue without driving out of my area. It seems impossible to keep the car dry let alone do a wash because of the weather. Any idea on what really is causing this, how to avoid or prevent, and how best to remove the small spots once it warms up?