Yes, that's what people imagine is happening when talking hydrogen powdered cars. But I believe that electrolysis is so inefficient that it's not a realistic option for producing hydrogen on an industrial scale. This leaves us with breaking down hydrocarbons, hardly a "green" option.

Sounds too high for something like energy storage but I assume that is in the ballpark for reasonable car pricing from the phrasing of the report.

Also honestly we could use "good enough" ways of reducing emissions. Waiting for perfect would be a bad idea.