Under bumper scratch

[07WYarisRS]

For most deep scratches I'll start by wet sanding the area around the scratch lightly with 800 grit. Make sure there are no burrs in the scratsh that will sit higher then the undamaged area.

Then use a paint touch up pen/brush and fill in the scartch. This may take several coats. Try not to get any paint on the area not scratched, just fill in the scratch. Once it has dried overnight use a fine point sanding pen or a piece of folded sand paper and lightly sand the filled scratch to beld it to the same height as the undamaged area then lightly wetsand the entire area with 1000 grit to blend the scratch with the undamged paint. Do not chase any low spots, instead fill them and re sand.
Remember you don't have to sand the undamaged area very much before you go through the paint so focus all your sanding on the scratch and do as little sanding as possible to blend it.
Once it's blended use ScratchX on a clean rag to buff out the dull paint left from wet sanding.

Alway wet sand and add a little dish soap to the water as a lubricant.