You can use a heat gun to remove scratches in plastic.
You have to go slow with the heat, but the scratches will simply melt away. Use caution and hold the heat gun about 4-6 inches from the surface. Work the heat in and out and round and round. Don't let the heat gun sit in one place too long.
Do it wrong and you will get a shiny spot on your dash. Do it right....the scratch will be gone.
That little scratch should come out in a couple minutes.
Paul