To introduce at the same time navigation map information, headway and lane deviation warnings and other information to the driver is not feasible with today's vehicles' interior design. Not only driver overload may result to dangers to his/her safety but also there is a total lack of appropriate space and modalities for all these Advanced Driver Assistant (ADA) systems input and output devices. Within the context of COMUNICAR project (IST-1999-11595) an innovative integrated multimedia human machine interface (HMI) design approach for in vehicle Advanced Driver Assistant Systems (ADAS) applications is being designed with regards to the optimum location of different I/O elements (visual screens, audio messages, tactile elements etc.) within today's vehicle interior. This is especially realized for the input systems of ADAS which use many technologies such as keyboards, touch screens, joystick, mouse etc. Within this paper firstly the problem of the huge amount of information directed at the same time to the driver is explained and the solution of COMUNICAR is described. This solution is based to the design and development of an integrated HMI which, taking into account the traffic and environmental conditions and the driver's workload, decides if, when and how to present the different information coming from the different systems of the car (telematic, ADAS, etc.) to the driver. Then the concept of the Intelligent Information Manager is presented. The latter is the core element of the COMUNICAR multimedia HMI. More specifically the Intelligent Information Manager (IM) is based on a multi-parametric logical structure that controls and optimises the interaction between driver and on-board information system on the basis of the traffic and environmental conditions and the level of activities of the driver in the primary task. The design of the Intelligent Information Manager involves three major steps, namely the definition of functions to be integrated to the COMUNICAR multimedia HMI (Content plan), the identification of the input devices and the candidate format for the output displays (Communication Plan) and the rules with which the HMI maintains tolerable the driver's workload (Channel Harmonisation Plan).