Removing rust from body paint

Hello all
can you suggest a good way to remove rust streaks from paint (without using any commecial products)?

There are vertical rust streaks that oddly enough start from the fiberglas roof (how can fiberglass rust?) and goes all the way down to bottom edge of aluminum body which I am trying to remove.

thanks in advance

A not to aggressive polish like "T Cut" or similar should do it. If that fails try and get some cutting paste from your local body shop supplier, go easy with the pressure you apply it may be better to show a little ageing than rub through the paint.