As the saying goes: "What goes around, comes around". The very first modern serial hybrid was designed and built by Victor Wouk in 1974 using a Wankel gas engine from a Mazda car as a generator, and an electric motor attach to the transmission of a 1972 Buick Wildcat. He submitted his prototype to the EPA who did the very first emission tests. The hybrid passed the test and had high MPG but the EPA never approved it. So Wouk stopped the project but submitted papers of his work to the SAE. The top engineer at Toyota read Wouk's papers and decided to do his own prototype, giving birth to the Prius. Wouk later bought one.
Now Mazda is reviving Wouk's original idea with the same Wankel rotary engine as the "range extender. If he were alive, Wouk would be happy that Mazda used HIS idea, completing a full circle. But I bet that he would be now driving a Chevy Volt!