This is a thought I'd like to bounce off the community,. Would it be possible to set up the material for the body as dirty windscreen and have a dirt alpha so over the corse of the race the body gets dirty?
yes I believe they already have damage layers in the shaders for this. for both window and carbody. the window version I believe was already in rF1.
for the carbody it's bump cube specular map add alpha reflect T1 lerp T2 vertex and for the windshield inside and windshield outside.