If you have an anodized brushed aluminum panel, here is how to clean it:
Goof Off will not harm the panel, but the brushed quality may prevent you from having success. Anodizing is very hard and sharp- many materials will cling to its grooves. You need a get a 3M Scotchbright dishscrubbing pad, the kind that is either green (often found on the backside of 3M sponges) or maroon.
You treat the panel with the cleaner- Goof Off, Windex, alchohol, WD-40. Then you wipe the cleaner off with the pad, being careful to **follow the grain** that is brushed into the panel. **DO NOT** sand back and forth (if you get too aggressive you will eventually take the anodizing off too)- go in one direction, towards the closest edge of the panel that the grain is headed towards.
Anodized finishes are very hard, so your fingernails and skin can leave small 'scratches' in the surface. The same is true of metal tools- often you can lift scratches out by simply using the Scotchbright pad without any chemical cleaner so long as the pad is clean.
If a scratch penetrated to the aluminum underneath you are screwed. Do not use the Scotchbright over any silkscreen, unless the screen is anodized on.
This all comes from one of the country's leading anodizing houses which does work for the military as well as several very well-known high end audio manufacturers.