I treat it in a lot of ways like my camera lens. I'll use a bulb blower to lightly blow off heavy dust followed by a natural bristle artist's brush. If there are spots that remain that need any pressure, I will use a lightly moistened PEC pad (from the optic industry) to "very" gently remove the spot. Some good optic fluids mentioned so far. I often use distilled water. This works very well on the plasma TV screen also.

However, I find high gloss black/dark coated plastic to be almost impossible to keep from being marked if frequent cleaning is necessary. The bezels around flat screens and the kids Play Station come to mind.

Of course, it always used in the worst possible spots in vehicles, like around the gear selector. One is really lucky if they can even get a new car with these areas pristine. I often wonder how much is actually done during factory installation. Our most recent purchase was OK. The instrument cluster and touch screen were pretty good, but the gear selector and HVAC monitor strip still look like birds danced on them.

Best,

Mike C.