Thanks for the reference image link, that is certainly a great model, very well rendered. I understand what you are saying, though the reference image is still highly reflective (of the environment map, not the actual scene). You can clearly see reflected detail in the background, like a building above the front wheel and a fence across the windows. I think the reason the reflected background looks as good as it does is that it has large areas of black and has a high contrast, which serves to reveal the shape of the reflecting surface rather than disguise it. This is definitely a point worth remembering and I thank you for pointing it out!
I intend the final scene to be an indoor shot, as if the car is on display at a motor show or something like that. It will be illuminated by several spot lights, and the background will be very dark. Once I have finalised the material settings (for all the materials, not just the duco) the final render may appear closer to the Ferrari you linked to. At this stage the duco colour is entirely unknown, I will try a few different colours once the final scene is fully rigged.