Today, I was thinking about how Dinoco is the Pixar version of Sunoco. Then it hit me. Sunoco is the official fuel of NASCAR, but Pixar made the parody of it before Cars came out. How in the world did that work out!? Tell me what you think about this.
Just a theory:
John Lasseter has always been a big fan of racing, and maybe during the production of Toy Story, he decided to “cameo” Sunoco fuel for the gas station sequence. Then when the ideas began to fly about Cars, he thought, “That would work perfectly with the whole idea of racing!” and they used it as the main sponsor (as well as the official fuel) for the races. 
I dunno. An idea, anyhow. But it makes sense.
little chef