Second day I owned my new CX-30 I wiped some dust off with a dry towel and you'd have thought I used 200 grit sand paper. Luckily I was able to get the scratches out with a microfiber cloth and Novus plastic polish I had for other projects. Here's a good kit of it:

https://www.amazon.com/NOVUS-PK2-2-Plastic-Scratch-Remover-Bottles/dp/B000B4UGZE

My scratches weren't so deep and I got away with only using #2 (a few times), then #1, but it might be worth getting all three steps just in case:

https://www.amazon.com/Novus-7136-Plastic-Polish-Kit/dp/B002UD0GIG

Thanks for clarifying. In that case there are a few things you can try. A glass file will get you the original plastic shine and is really good for flat surfaces. This is the buffing compound I use, which does a good job and works for paints and is safe for plastic. You can also try nail buffing blocks.

The original plastic surface is really shiny because it's so smooth. So if you want it to look like plastic again you have to polish it after sanding with 2500 grit.