Interior Outlines?

Hey guys, I am currently using the Toon Lighted/Outline shader and I was wondering if I could replicate the "SmGroup" option from 3DS Max's Ink & Paint shader in Unity?

It basically allows there to be outlines on the interior of the mesh if two different polygons, each with their own shading group, are beside one another, oppose to only having the outlines form around the mesh. This would allow things like defining muscles and such without the need for texturing them in, which can be a pain. I'm not sure if it already does this, but you can kind of see the effect when you rotate the model about, but they're still not quite as precise as 3DS Max's.

If anyone could lend me a hand at adding some form of this option to the Toon Lighted/Outline or Toon Basic/Outline shader(s), it would be greatly appreciated.

Outline Shader: http://pastie.org/3608677