Rain, dirt, damage showing at once in Windshield material

I am using "Windshield Outside" material and have made corresponding maps for all the different layers. They are working fine, but the problem is that they all are showing at once. I assume that given layer only shows up when required conditions are met? Am I doing something wrong or is this unfinished feature in the beta?

 

...Any help?

 

i get the same, so i just dont use these shaders untill ISI finish them and release documentation.