Re: Render layers losing MR shaders?

Some things to check (I know you're old mates, but can't be too careful with the basics):

Is the shader assigned to that object the same one as on the master layer, or is it an override? Overriding shaders on a per-face basis can cause them to become disconnected.

Is the MR renderer selected/overridden for Layer 1? I assume Maya's default renderer wouldn't know what to do with the car paint shader.

Try creating a new object with the same shader assigned to it... maybe even in a new scene. That might help narrow down the problem.

-Steve