First, you're smart for asking this question as it's much better to work safe and avoid scratching or marring the plastic face of gauges, instruments and displays than trying to somehow polish scratches out of these surfaces.
1. Their location makes it difficult to hand polish and in most cases working by machine is even more difficult.
2. Plastic is changing but no matter what type of plastic you're working on it's at least as difficult if not more to work on plastic as it is clearcoat paints.
Tips...
Try to blow or vacuum dust off first. If the dust can be removed without pushing it, (wiping), the plastic surface this is automatically safer.
2. Use a product formulated for plastic like Meguiar's M18 Clear Plastic Detailer. The last thing you want to use is some type of liquid that stains the surface.
3. Use a clean, soft fluffy microfiber towel so any dust can bury into the nap.
4. Never use a shop towel or paper towels.
Hope this helps...
Be careful using glass cleaners. Most glass cleaners contain alcohol and while safe for glass and in most cases safe for plastic, you just never know and if it does cause a problem... fixing plastic on gauges can be difficult. It's also hard to test product on inconspicuous areas... there's usually no inconspicuous area on dash gauges, instruments and panels.
There is dust on it, and since I don't want to scratch the plastic, wiping it off with a damp cloth seems counter-intuitive to me. So, you're help and insight is much appreciated!
