Original Equipment Manufacturers (OEMs) and their suppliers are confronted with a paradigm shift from Variant Production to Mass Customization. In contrast to variants, mass customized vehicles are configured according to each customer's individual requirements and, nevertheless, are sold at a price comparable to standard vehicles. In order to economically offer customized vehicles and after-sales services, OEMs and suppliers must closely cooperate and apply appropriate information management approaches. Starting with an overview of interconnected business processes between an OEM and supplier, the focus of this contribution lies on grasping customer's requirements as well as generating and utilizing a customer's profile. Consistency of customer's requirements is checked by car configuration and simulation tools. Subsequently, the individual customer's order is transferred into the OEM's and supplier's data management systems. In addition to data generated during the order and production process, the customer's profile is supplemented step by step during car use. Based on a detailed customer's profile, individualized after-sales services can be offered which fulfil each customer's unique requirements and thus significantly contribute to the company's revenue as well as to high customer loyalty rates.