I understand how to use a normal map, and methods for making it from a texture map, but the render option for this is a bit of a mystery because I have a render  not really a texture so I am trying to figure the real practical use of this is. Like a preview?  What is the best way to get a useable normal map out of Carrara? Got all the inagoni plugins. I know agrooves can have some advantages here also.

No need to think outside the box....
    Just make it invisible.