Keep the gas engines but run them on hydrogen. Saw a hot rod pick up w/ V-8 on hydrogen and it is zero emmissions.
Not so fast there.... In theory it's a great idea with H2O as the only emission, but I'm always leery when someone says "zero emissions." as it's almost never the case. It's usually just a shifting of emissions that creates its own set of problems. What's not being told about Hydrogen is the gas is generated as a byproduct of fossil fuels. From New Scientist: "96% of hydrogen is made directly from fossil fuels – mostly natural gas, followed by coal and then oil. This overwhelmingly uses a process known as steam reformation that releases carbon dioxide."
It may not be as clean and green as they claim, and you have to wonder that since the number one greenhouse gas is water vapor, is adding more a good idea? However, if the vehicle condenses the water vapor into droplets, they are harmless.
As an aside, I know a couple with a Hydrogen-fueled Toyota Mirai that lives near me and they told me there are only two fueling stations in southern California - 40 miles south to San Diego or 70 miles north to L.A. Best not be running low and stuck in traffic!