[Shevelle]

Take it to a truck wash. You can usually find one near a truck stop. It's easy, it's inexpensive, and they do a hell of a good job getting the black streaks off. We were amazed how good the trailers looked when we took them there.

We have had success also using Aluminum Brightener. But you have to be really careful not to mix it too strong. Probably about a pint in a 5 gallon bucket of water. It gets the white aluminum looking like new but if you get it on the diamond plate and its mixed too strong or allowed to sit there too long it can discolor it.