Originally Posted by
xr2wishy
you could use fine wet and dry sand paper, 1000grit f it's really bad then autosol over that for hours.
personally just persevere with autosol or meguires.
If it's a persistent stain or a scratch, then I'd go with fine wet and dry using WD40 or a thin machine oil as a lubricant. The Aluminium will be left dull afterward but can easily be buffed back to a shine with any decent metal polish.