at the same time, you could just create a shader (blinn or phong would be best) and just increase the reflectivity to 1... and then raytrace your scene. a shader like that will reflect like a mirror.


if you do, however, check out esion's post on his robot, it looks way cool. had there not been an hdri image, i believe it would look closer to a non-mental ray render.

so if you are willing to sacrifice rendering time for looks, go with his. you won't be disappointed. on the other hand, increasing reflectivity on the shader you want to look metallic and then raytracing should give you something close.