We propose and discuss an overlay architecture relying on a mobile ad hoc network, called Arigatoni on wheels (Ariwheels for short). More specifically, Ariwheels is a virtual network organization that is designed for a vehicular network underlay environment. It provides efficient and transparent service advertising and retrieves services carried by on-board and roadside nodes. The paper outlines application scenarios for Ariwheels and evaluates them through simulation in a realistic vehicular environment.