[Runtime Feature]: Clear coat support for opaque shader

What is the context of the feature/improvement?

What?

Clear coat on a is a transparent, glossy final layer of paint applied over the base coat, providing protection and enhancing the appearance. I suggest adding clear coat support to the remix shader.

Please describe the feature/improvement?

Why?

For my specific request, I need clear coat for car paint (Need For Speed: Underground 2). clear coat is one of the essential parts of car paint and without it, it's quite difficult to make a a convincing/pleasing car paint material.

Other games that might benefit from this change.
All supported Need for speed games (cars)
All supported GTA games (cars)
Garry's Mod (Various car mods among other things)
Star Wars Republic Commando (Various spacecraft)
Half Life 2 (prop cars [Take the bait])
Flatout 1 and 2 (cars)
And others that feature cars, varnish, gloss coated wood etc....

What would be your solution? (optional)

My solution would be adding clear coat support to the remix material ¯_(ツ)_/¯
P.S I probably wrote the wrong things in the wrong boxes because I initially didn't realize that I was required to fill out two different sections. psps I have been awake for more than 24 hours at the time of writing so I apologize for confusing writing.

Version

1.0

Media

In the following image, these results were achieved after quite some experimentation, but it lacks the depth of a rough base layer and a a glossy clear coat layer:

Blender render for demonstration purposes. What the material could look like with clear coat.

The issue identifies the remix shader as the target but names no repository files, entry points, or tests. Start by locating the opaque material and shader implementation, then determine how a clear-coat layer should be represented and validated. Done would mean supported clear-coat behavior with tests or visual validation for the described car-paint use case.