Modern military vehicles require a large variety of sensors, actuators, effectors, mechanical and electro-mechanical sub-systems to function and satisfy the ever-growing operational needs. In order to be inducted into a military vehicle, these sub-systems need to fulfil certain standardization criteria. The NATO Generic Vehicle Architecture (NGVA) is such a standard for military vehicles. It proposes an open architecture approach to land vehicle platform design and integration, and standardizes the interfaces and protocols of vehicle sub-systems. NGVA lays down the requirements for a sub-system to be compliant through its Allied Engineering Publications (AEPs) and specifies how Verification and Validation (V&V) of entire NGVA systems can be conducted. In case of a configuration change or integration of new NGVA-compliant sub-systems, a costly re-verification of the whole vehicle is undesired. In order to avoid it, required and intended interactions between the various sub-systems in the vehicle are to be specified which lead to stable vehicle configurations satisfying all the requirements for generic and specific use cases. In this paper, we propose a V&V methodology for NGVA with which the integration of a new sub-system can be verified and validated along with the existing functional sub-systems.