The metallic paint is a mix of two layers. The Base layer which is basically the color of the paint and a Coating Layer on top of that.

• Start with a Basic Layer.
• Select a dark color for the Diffuse Channel.
• Use the same color in the Reflection Channel but brighter.
• Increase the Extinction Coefficient to a value of 2.00.
• Increase Roughness to 35%.
• Add a Coating Layer.

To create a more realistic car paint, we need to add an extra layer for the Metallic Flakes. Starting from the previous Metallic Paint:

• Create a Glossy Layer and move it between the two layers.
• Click on the Texture button of the Diffuse Channel (image 6).
• Select the 1st icon of the Texture Lab,  click on the Color icon and select a Color.
• Select the button right below it, click on the Bitmap icon and select a Flakes pattern.
• Use the same grayscale image in the Layer’s Weight channel.
• Finally, load a normal map version of the flakes texture in the Bump Channel and activate Normal Mapping (image 7).