I believe it's rain drops against the monitor/vr screen (use case could be to simulate a wet windscreen on chase cam) Edit: Or could be the post above
or it could be the post above this one, am regularly delusional. Edit: Also it is in the Post processing section so most likely Shurikan is correct and I am just full of it... More Edit: yeah, Shurikan is absolutely correct and I am just a filthy misinformer. shocking I know.