Albrecht von Geortz (designer of BMW503 amd BMW507) and Yamaha tried to sell the A550X project to Nissan. Nissan did not buy the project.
But Nissan did like the idea, so they developed their own sportscar, later sold under diff. names as Nissan Fairlady
and Datsun 240Z The inspiration from the Yamaha A550X is distinct to my mind.
After Nissan, Yamaha and Goertz tried to sell the project to Toyota.
Neither Toyota liked the project and did not buy the it.
Like Nissan, Toyota liked the idea. They developed their own sportscar: Toyota 2000GT
Toyota's inspiration from the A550X project is not as distinct as by Nissan's sportscar.
Too bad the Yamaha A550X was not put into production.