Screenspace Reflections in HDRP: How can we control reflectivity of a surface?

SSR is amazingly great for making cars look realistic, but the problem is the reflections are often *too* shiny, like mirrors, which isn't realistic at all unless you are seeing a car at just the right angle in just the right lighting.

As far as I can tell, there is no setting for how reflective to make it - you can either disable SSR entirely for a particular material, either through checkbox or through material smoothness, oryou can "fade" all SSR in the entire scene towards white (but there really isn't very granular control over that, it seems to be a LERP from the minimum smoothness to the maximum, which is a very small difference when minimum smoothness for SSR is like 0.9).

What we'd like would be to control the reflection transparency, so the cars' paint colors would shine through more. Are there any settings I'm unaware of where we can better control this? We are using 2019.1, HDRP version 5.16.1.

Also, we are using the Unity Measured Materials pack, with its special car-paint shader.

 

There is no built in option to make the reflection effect from the postprocess more transparent. However you could make the material less smooth to make the reflection more dispersed, which will make whatever behind it more visible.