two things come to mind:

 - when you've duplicated your "body chick" to a "hair chick" and altered materials, then you just might take the latter and Conform To the first. Both figures have the same bone structure, and that saves you the reposing efforts. Just be sure to take the first one for posing.

 - ray bias is measured in your own units (0.3 is default for inches, so when units are meters then it says 0.07620). It is meant to avoid unwanted reflections of surface parts resulting from the displacement (mapped or modelled) of the same surface. It results in everything within that range being ignored in reflction.
But the car hood does not have any displacements at all. So, just set raybias to 0.000000
(for instance, eyes should have a raybias of 1" to avoid the nose being reflected. Facial skin reflectivity should also have raybias of 1" otherwise the ears become visible when backlighing, thanks to fresnel).  

- - - - - 

Usually I'm wrong. But to be effective and efficient, I don't need to be correct or accurate.

visit www.aRtBeeWeb.nl (works) or Missing Manuals (tutorials & reviews) - both need an update though