While this is an interesting variant, it faces the same problem that vehicle-2-vehicle communication based on the DSRC and 802.11p protocols does.
Nobody has ever, as far as I know, built a network technology where you must network with random strangers you encounter out in the physical world. You can't build that because there is no value to the first people to install the tech, no value even to the first million in a country with 250 million cars like the USA. The odds of any 2 given cars being able to talk is one in 62,000 at that point. How can you sell a tech that provides no value to the first millions of customers? Even with the legal mandate they are hoping for, it will take decades before there is wide deployment of the 2013 designed technology that is then very obsolete.
I explained this in more detail in my series on V2V at http://ideas.4brad.com/tags/v2v