On some cars, there is a bug with the windscreen reflections where the bottom part of the windscreen reflects the road surface in very low resolution on the inside of the windscreen. This is very off...
Ideas
Very bad in Citroen C4 (WRC 1997-2011 class) also and can be much more cars. Especially if u run car reflection quality ultra-low (as it's very demanding setting) it creates huge white blob that shakes like crazy (could cause issues to persons with sensitivity to flashing stuff etc).