DUDENHOFEN, Germany — European auto manufacturers have achieved a milestone in vehicle-to-vehicle communication. This week at the Opel proving grounds, they held the first road test of what they are calling 'Car 2 Car' technology that lets cars talk to each other about such things as road conditions and vehicle status.The simulations included a motorcycle at an intersection, a stationary vehicle on the road, a construction zone and a police car in action. Among the vehicles used were a Volkswagen Passat TDI, a Volkswagen GTI, a Honda motorcycle and a Volvo commercial truck. The vehicle-to-vehicle research aims to create a universal standard for communication between automobiles. Using wireless technology, vehicles can transmit data like vehicle speed, engine speed or the status of hazard flashers.The road test was carried out by the Car 2 Car Communication Consortium, an organization of European vehicle manufacturers seeking to improve road safety and efficiency via inter-vehicle communication. Members include Audi, BMW, Daimler, Fiat, Honda, Opel, Renault, Volkswagen and Volvo.Inside Line says: Industry collaboration on vehicle-to-vehicle communication may make this technology a production reality in the near future. — Eric Tingwall, Correspondent