Hi,
So i am on a dilemma here.
I modelled this car recently.
3D Dodge Viper RT/10 - YouTube

It was part of my course on advanced Maya.
Now i wanted to make a new car, but modeled in Polygons, for my portfolio to show my skills with it, and to go into more detail that i didnt go with the Viper with NURBS.
But my teacher always told me to do lowpoly base models and then transform them into subdivisions, but i came across one error rendering it with mental ray, and search for it and as it seems i cant assign multiple shaders at the subdivision surfaces and render them with mental ray.
The Viper was rendered with MR, and i really wanted to keep using it as a main Render engine, so i ask you what path shall i take now.

(Note: i am using Maya 2012, and the info i found on the MR problem seemed outdated, about 8.5 Maya, although the error persists)

Shall i increase edge loops and get more definition with them, (seems to me to have much work to it, since i want to avoid lots of edges on the windows and some other areas, and i would have to create some Poles to avoid edge loops along the entire car, in my opinion)?

Shall i transform to subdivision, increase the detail where i want and then transform again to polygon?

Or is there a solution to my problem in the first place.

In the images you can see the low poly car, and so far with all normals soften i've been having good render results already, but as you can see on the other image i would like to improve the quality and detail on those corners so they wouldnt be so square, and to be able to have more detail in the chromed parts.

Thank you


[EDITED]
PS. I noticed something strange, when i converted into subdivision, all the faces became invisible, (not invisible, but with no shader) like it was on wireframe, then i needed to re-assign the shader on the car, and it was then that i came across the error problem when i assigned diferent materials to diferent subdiv faces. And the car rendered came appeared invisible.