The increasing role of software in vehicles presents great opportunities for enhanced smart city mobility solutions. Among those, is enabling the interactions of vehicles with one another and other digital objects, such as functions, in a shared digital space. In such a digital space, representations of vehicles and functions can interact and cooperate with each other. This thesis explores the design and implementation of digital Cooperation Spaces (CSs) to facilitate enhanced cooperation and coordination among Software-Defined Vehicles, infrastructure elements, functions and other stakeholders in a smart city environment. The core concept involves creating digital twins of physical entities within the CSs, enabling them to communicate, collaborate, and make informed decisions. Motivated by the complexity of modern transportation and the need for adaptive solutions, this work develops use cases and requirements for a cooperative system supporting the dynamic entry and exit of digital objects. Based on these, we outline the architectural considerations for developing such a system. Using these discussed considerations, this work presents a system architecture for such a cooperation system, along with a proof-of-concept implementation showcasing fundamental functionalities. This prototype implementation features the CSs and digital objects such as digital twins of vehicles and mobility functions. Furthermore, a simulation visualizes vehicles driving in a simulated urban environment and interacting with a CS and relevant functions. Then, the implementation is tested with an increasing number of participants in the CS to identify potential bottlenecks and future research areas. The work also highlights remaining challenges and opportunities for future investigation. Thereby, these findings guide the development and real world deployment of such a cooperation system and contribute to the creation of more sustainable and efficient urban environments and mobility solutions.