Attach a trailer to a vehicle and its available signals may change while applications already running. Vehicle configuration changes and OTA updates create the same challenge: an application coupled to fixed endpoints or a static tree of every signal any vehicle might expose cannot easily discover the interface of a specific vehicle. This session argues for pairing the common data vocabulary of the COVESA Vehicle SignalSpecification (VSS) with a discoverable, data-centric runtime contract so applications can find and consume the data flows available on a specific vehicle as that set changes. We present an implementation that maps VSS-defined vehicle data into RTI Connext Cloud as data flows based on the OMG Data Distribution Service (DDS) standard, allowing applications to discover compatible publishers as they appear or disappear at runtime. The session examines how VSS defines shared vehicle-data semantics while DDS supplies automatic discovery and quality-of-service policies, an approach aligned with the data-oriented architecture proposed by AVCC TR-005. Because discovery must not imply unrestricted access, we will also examine how the OMG DDS Security standard supports participant authentication and fine-grained publish and subscribe permissions on mapped data flows. Using the changing vehicle signal set as a concrete scenario, we will identify the architecture decisions and limits involved in delivering vehicle-specific interfaces based on VSS. We will also explain how these interfaces can reduce integration coupling across vehicle brands and, with appropriate platform bindings or gateways, support applications deployed in vehicles, on mobile devices, and on the web.