That's not correct.

Quote:
Actually, one company in germany owned the basic patents, and all the big and most small manufacturers licensed them.

Mazda perfected the emission controls by 1974, and all licensees shared that. But few made vehicles after the Oil Crisis. Even NSU stopped making rotaries. Muscle car sales died in the USA along with most high-power engines until the mid-80s.

Mazda took a large risk, developed a lot of the answers but eventually went bankrupt. Ford and others bailed them out. But thanks to the big M we have these great engines in quantity. By the way, Ford sold their controlling interest in Mazda last year when Ford was bankrupt. Mazda are indpendent once again.