an interesting Mod idea. As for copyright, each company will have its own rules regarding every piece of material they own the rights to. You obviously cannot make this Mod commercial in anyway as that would be copyright infringement.

You might also want to consider the fact that yes you think you will be advertising their product to the world so to speak, but perhaps they don't want you to do that, hence why they copyrighted the products.

Good Luck.

P.S. I agree with Omanes wholeheartedly on this thread. Don't set your sights too high, you cannot get to the Finish without crossing the Start line.