Gold indice of reflexion is not linear. Reflexion color should be yellow (not white) and diffuse color a little bit orange.
An example made with the Indigo's gold nk data:
Is it just me or are the instructional pictures in the original post not opening full size and are stuck on small thumb nail images? I am trying to do the tutorial but the images are tiny, up to the gifting bit atm so it does not stick
Could it be the sampling setting of that particular material? Because the noise is not on the whole picture, it seems like only on the floor reflective material. I don't use Blender, so I don't know how it works. But this is what will I get sometimes if the sampling level in Mental Ray's blur reflection material is low.
Yeah it looks very good, like an Indigo render.
The headlight's chrome and polycarbonate materials, and antialiasing need minor tweaks then it will be perfect.