Systems of systems consist of independently owned, operated, and developed constituent systems that work together for mutual benefit. Co-opetitive systems of systems consist of constituent systems that in addition also compete. In this paper, we focus on quality requirement engineering for a constituent systems developer in such SoS. We discuss the needs and requirements of a structured quality requirements engineering process, with examples taken from the transportation domain, and find that there is a need for mediators and agreements between constituent systems developers to enable quality data exchange.