There are a two ways to handle objects that are close to the camera like your car:
A fallback large enough to cover the object: 
And your meshes still at layer 1.
OR
Keep the fallback region close to the camera:
And you move your meshes to Layer 3.
Unfortunately, both require that you don't exclude the sky from rendering.
I can see how excluding the sky while also having nearby objects could be useful. I don't think there's a good workaround for that, but I'll try to come up with something.