Accurate modeling of complex dynamic environments is a fundamental requirement in robotics and automotive applications. While grid-mapping approaches used to be limited to static settings, methods for dynamic occupancy grids have recently been developed, tracking spatial occupancy at a sub-object level, in every cell. In this paper, we present a generic dynamic occupancy grid tracker, which filters cell states and infers dynamics of the scene through the interaction of a grid-based and a particle-based model. These are set to represent different parts of the scene, and optimize particle allocation only to relevant areas, their predictions being fused accordingly. New hidden variables in the filtering process permit to address previously mishandled situations, like concurrent state predictions or specific filtering sensitivity. The presented method has been implemented, optimized on a GPU and tested on real-road conditions, embedded on an experimental vehicle.