A modular vehicle assembly system and methods for increased flexibility and adaptability of a high volume assembly facility which builds several vehicle models. In one example, the invention includes modular assembly equipment (AE) support pallets which are shipped to vendors for installation of selected AE equipment devices that are specific to a predetermined assembly operation and then validation tested prior to shipment. The modular AE pallets and AE devices are quickly installed and easily removable for maintenance or replacement. In other examples, modular AE support platforms and safety fencing are used to support ground level assembly operation and safer working environment.