As many have said, a clay bar will get out rail dust. Be careful that your dealer doesn't let some schmuck break out the orbital polisher on your truck. With this paint being so thin, I wouldn't wan't them trying to get it out with a buffer.
If I wanted to solve it quickly I would just wash her down with a dawn wash and then get after it with the clay bar. RE-WASH, then put on at least one coat of your favorite wax.
