Shadows with Two Directional Lights

I have two directions lights within my game scene. One for the environment without any shadows and other for the gameplay objects with shadows.

Now I can’t able to get shadows on gameplay objects like cars as per my this game. I have created a separate layer for cars to give shadows using separate directional light.

But I am not getting any shadows on cars, as per my above image reference. Within the same scene, I have other point light too. So a total of 3 lights in the same scene exists at present.

Here are rendering settings and shadows directional light inspector data:

Provide me some suggestions to get shadows on gameplay cars.

The light set with a culling mask of cars is only going to cast shadows onto objects on the cars layer from an object on the same layer. So a car will cast a show onto another car but not on the road unless the surface beneath it is also on that layer.
What you could do is use the one directional light and set the environment objects renderers to not cast a shadow.