Most communication between cars on the road involve shaking fists and words not suitable for a family publication. But the German Research Centre for Artificial Intelligence research project might change that.
Dubbed Smartweb, the system they're envisioning would involve various sensors on our cars, with information gleaned from those sensors passed on to other cars via an automotive P2P network. A BBC report on Smartweb gives an example where a car can deduce that it had passed over a slippery surface by correlating wheel traction information and the current temperature. That information would then be passed on to neighboring cars, which would then pass that information on to cars behind them. Drivers of those cars would receive some kind of warning that the road ahead is slippery. Other information like real-time traffic information and parking availability could also be relayed.
Smartweb hasn't actually been produced for the public as yet, but with partners like BMW and Daimler Chrysler on board, I'd expect to start seeing something like it in new cars in the next few years.