This is coming more from a digital illustrator than a 3D modeler so take it with a grain of salt. I really like the car it's a really good render of it, however I feel that the material looks more like a plastic than a metal, perhaps is the way the ligh bounces or that it looks way to round like there is no imperfections. Apart from that it really looks good.

A little tip for the background don't overdoo the depth of field since like this looks like the blur should get to the car itself, like the photo is taken with a camera focus of 2, if it was a bit softer the compositing would look fantastic.