Auto body repair & detailing: Removing rust film from paint, professional detailer, metal shavings

Question
I have a 2007 Versa and moved to New York from Az about a year ago.  I guess I haven't washed my car frequently enough here.

The paint has a grainy slightly rusted film all over it.  I park under a train and you can see what looks like rust fall from it sometimes.  I believe thats what is on my car.

I have taken it thru a regular automated car wash as well as had a guy pressure wash it, to no avail.

It is on the very surface of it and its not very visible.  The paint still has its gloss.  Its only when you get up close that you can see it and feel it when you run your fingers over the paint.  Otherwise, its not noticeable.

I know that buffing it would definitely fix this.  However,  I wonder if their is a product I can spray on as a presoak before taking it thru the car wash.  Something that can soak for several minutes and hopefully loosen up the film.

What do you think?

Answer
What you describe was originally called "rail dust". Vehicles got it from being transported by rail to a distribution center to local dealers. It still happens quite frequently even when being transported by truck. Frequency of washing would not have prevented the problem.

There is no "magical solution" that can be sprayed on the surface so that a carwash could remove it. The small metal shavings that are now rusting are imbedded in the paint surface and need some sort of friction to be removed. I have used automotive clay to remove the shavings. A wash with a chemical to neutralize the rust should follow. The car should be polished and waxed to can and seal the paint. This is quite pricey and must be done correctly to prevent paint damage. I would not suggest doing it yourself. Bring it to a "Professional" Detailer or Bodyshop that has experience in removing the shavings. I would not have the car buffed to remove the problem as this could lead to scratching of the paint surface.

If you are going to continue to park under the RR tracks, you might want to invest in a car cover after the metal removal has been done. Otherwise find a new parking spot away from the tracks. In the long run, if left untreated this will lead to paint breakdown.