For the studio lighting setup I always use "Lichtwannen" (Licht = light, Wannen = bowl) (Fig.22). This gives me a nice control over the reflection and the setup is pretty simple. As you can see, I only used a tube and a plan and applied a Vraymtl material to it. In the diffuse map I put an output map with an intensity of 1,5. In the output map I put a gradient ramp going from black to white and black again (Fig.23-24). Make sure that you turn off "Cast Shadow" in the object properties for both "Lichtwannen" (Fig.25). For the studio light I only used a skylight with the intensity set to 1. This gives me those soft, studio car shadows (Fig.26).
If you are using GI for your light solution, make sure you turn off "Default Lights" (Fig.27). The reason why I used a secondary rays bias value greater than 0 here is that, I had some overlapping meshes and even some objects with a height of "0", and VRay tends to make ugly artifacts when this happens. So I used 0,01 to get rid of those render errors. For the image sampler I used Catmul Rom, because this filter gives me a sharp render result (Fig.28). Indirect illumination settings can be seen in Fig.29, the Irradiance map settings can be seen in Fig.30, and finally my settings for the light cache are in Fig.31.