Vehicle communications are becoming increasingly popular, propelled by navigation safety requirements and by the investments of car manufacturers and Public Transport Authorities. The primary VANET's goal is to increase road safety. To achieve this, the vehicles act as sensors and exchange warnings or – more generally – telematics information (like current speed, location or ESP activity) that enables the drivers to react early to abnormal and potentially dangerous situations like accidents, traffic jams or glaze. In this context, the application of the ambient intelligence technology raises the vehicle capacity to manage its active security. In this article, we propose a new functional model for a vehicle that reacts as a ambient component in its environment. We assume that each vehicle contains a speed sensor. A Wireless Sensor Network is created between vehicles. The security state of each vehicle depends from telematics information exchanged periodically between neighbors. We opted to assemble the simulation of the model with the Castalia-OMNET++ Tools language.