Toyota and Mazda — the two Japanese automotive groups most sceptical about electric vehicle technology — have finally revealed plans to mass-produce battery-powered cars. They are late to a game that most of the world’s carmakers — including Volkswagen, Daimler, General Motors and Jaguar Land Rover are already playing, as they confront the rise of US electric vehicle start-up Tesla.  But, even as many see a golden age of electric vehicles just around the next corner, it is hard to ignore a sense of unease privately expressed by some Japanese car executives as the industry makes a unified drive towards electrification.  In announcing their intentions, both Toyota and Mazda stressed that they had no choice but to prepare an electric vehicle offering to meet stringent regulations on carbon dioxide emissions in both China and the US. Their decisions were passive, rather than a proactive move to capture the electric vehicle market. Neither indicated they had made any major breakthroughs in battery technology — nor did they express confidence in making money from electric vehicles.