A weakening yen has emerged as a windfall for the country's automakers, helping buoy results just when they need it most amid pinched production and derailed deliveries.

Japan's automakers are stoking R&D investment to meet mounting demand for a staggering array of technologies. Toyota by far outpaces the pack.

The Corolla Cross H2 Concept is just one of many advancements in hydrogen combustion that Toyota rolled out at Fuji Speedway. Toyota is about 40 percent of the way toward commercializing its hydrogen combustion technology, a top executive says.