Just popping a bit of fresnel multiplied with the diffuse in the emissive channel is a simple trick, using a very small number will basically nullify it sunlight, but will make it pop a bit more in shadow. Cheaty and not correct, but works decently.
Is there a way in UDK to get normals to pop while in ambient shadow? Of course there is no direct sun light on these areas so they technically would never have normal detail, but normal maps are just here to help fake detail we cant model in. So in the real world, even these areas in shadow would still have some depth, not…