The ubiquitous Vehicle-to-Everything (V2X) connectivity enables successful deployments of emerging vehicular services around the world. However, geographical cross-border scenarios are challenging for vehicular services deployments over heterogeneous infrastructure and at the same time vehicles to maintain seamless service connectivity across borders. In this paper, we present the development and validation of an experimental vehicle On-Board Unit (OBU) for the execution of Anticipated Cooperative Collision Avoidance (ACCA) services in cross-border scenarios. The OBU flexibly supports the integration of different V2X protocols to communicate with heterogeneous cloud-based services offered by different Original Equipment Manufacturers (OEMs) within the ACCA service infrastructure.