Safety, privacy, efficiency and cybersecurity (SPEC) properties are mandatory in vehicular networks. Owing to intrinsic limitations, the V2X framework and related communicating autonomous vehicles are inadequate. We explore the CMX framework (Coordinated Mobility for X = SPEC), Next Generation Vehicles (NGVs), and protocols for safety-critical inter-vehicle communications and agreements that solve problems left open in the V2X framework. Then, we focus on cyberattacks and physical attacks against isolated NGVs and cohorts of NGVs. The cyberphysical security analysis investigates more than 20 attacks and demonstrates that the goal set for CMX is verified. In the presence of attacks, safety is never compromised, possibly at the expense of diminished efficiency.