This paper describes a reusable generic dynamic model that can assemble models of specific vehicles at runtime. This model notes the distinction between attributes unique to each model, i.e. models of subsystems and their force and moment contributions to kinetics, and those elements generic to all dynamic models, i.e. kinematics, numerical integration, and reference frame transformations. The generic dynamic model views dynamic models as a combination of basic services common to all models, and components that provide the unique attributes of individual models. The encapsulation of basic services into reusable generic models reduces development time and cost, while the ability to change reference frames allows the fidelity of the kinematics to be set and changed at runtime.