Shading Cars

If you don't have your wheel opened in Blender, go ahead and import it. Importing the model

To be able to see the texture, turn on texture mode in the bottom of your view port. Setting to texture mode

It is really important to set the correct render settings. To do so, head over to the Properties panel, usually to be found on the right side. Scroll down to Shading and disable Textures as shown below: Setting the right Blender settings

It is also important to have a vertex color channel on your object. It can be found in the Object Data tab of the Properties panel. If there is none present, Press the + button. Make sure the camera is visible on the channel you want to bake the light onto. Create vertex channel

Now it's time to create your light source. Hit SHIFT A and select a lamp of your choice. Since car wheels rotate, we need the lighting to be symmetrical. A Hemisphere light will give us the most evenly distributed light. Create Lamp

You need to rotate the lamp to show towards your wheel. This is also needed for an even light distribution. Rotate the lamp

Make sure your wheel is selected by right-clicking it (it needs to have the orange outline). Also in the Properties panel: The baking options. It can be found at the bottom of the Render tab. Important: Select Bake to Vertex Color, Full Render. Then press Bake. Bake settings

After pressing bake, your wheel should look like this: Result

You can press Bake again for a stronger effect. Result 2x bake

Advanced: If you feel like experimenting, select your lamp and tweak the settings. Select a different light source, tweak the strength or even its color. advanced settings