How do I add more than 8 decals to an object? I'm trying to add multiple decals to an object. For example a race car with all the sponsorship logos. The method I tried restricts the number of decals to the number of UV maps that I can create in blender which is 8.

This is the link to how the nodes are setup.He sets up the nodes at roughly 10-12 minutes in.

https://vimeo.com/36632196

So is there a better method of doing it where i can use more than 8 decals?
Image above.  Rendered image with two imagined logos on particular faces.


Image above.  UV Maps.  Color Blue used to increase visibility of Seams.

Mapping Extension set to Clip.
Even if you see Blender Render the UV Map applies to Cycles Render as well. Combined with the video tutorials you have seen you can do this. Note the part of UV is off the image which is what I want.  The Clip setting allows us to exclude modifications of color from parts of the mesh.  Please click to see larger image.

What is presented here is a quick summary, not a tutorial.