This work considers the problem of decentralized coordination between multiple non-holonomic vehicles, each navigating to a specified goal. By augmenting the Generalized Roundabout Policy (GRP), which guarantees collision avoidance, this paper improves the performance and liveness characteristics for such problems. These gains are achieved by integrating a second hybrid policy with GRP that updates the desired direction for each vehicle based on a dynamic priority scheme. In this scheme, minimalistic communication between vehicles is employed, such that information is periodically exchanged when changes in the high-level operating mode or prioritization occur. This information exchange is taking place only locally and data are exchanged only between neighboring vehicles. Additionally, each agent selects a control using only this local information and rules established by the two underlying hybrid automata. The proposed technique scales well due to its decentralized nature and as the computational complexity depends on the maximum number of vehicles in communication range for a vehicle. This paper presents simulations which show that the proposed approach can solve problems faster than using GRP alone, as well as solve instances in which GRP fails to find a solution, with minimal communication and computational overhead.