Recently, I discovered that it is possible to appear more particles in the game, including sparks. Just edit the command line:
<particles enabled = "true" distancescale = "1.0" rate = "1.0" High = "true" />
Where this "rate", change from 1.0, for your personal taste, until maximum of 10.0
I use 3.5. This is already even better emissions from sparks, as well as rain spray, smoke and dust more incorporated and realistic.
You can test other values, even in the maximum 10.
Note:
FILE PATH EDIT, Documents\My Games\F1 2019\hardwaresettings.config;