Many of these were being worked on with Boeing Vertol, who showed both the prototype SOAC car and the design of their LRV. Similar vehicles were also being developed by other aviation firms, especially Rohr. Rohr was showing their own subway cars that were being produced for BART and the initial models of their proposals for the Washington Metro, as well as Transbus designs from their recently purchased Flxible bus division, who were working on what would emerge a few years later as the Flxible Metro.