I'm shaking the tree this afternoon with a phone call to a connected friend.
Also, I'm quite willing to make a road trip to the hydrogen fuel cell company in KS that has a photo online of their Tesla Model S charging. I included a photo and description of this in my submission but there's nothing more compelling than a video showing "dead Model S > Plug into stationary fuel cell > Model S drives away."
The distinction here, in addition to "hydrogen power capable" is that batteries don't power a car, despite the common usage of the term. Batteries store energy, they don't create it. Our Teslas are being powered by whatever puts energy in the battery: solar, natural gas, hydroelectric, wind, coal, etc. In the same way, the hydrogen powered car is not directly consuming hydrogen to propel itself: the fuel cell is consuming hydrogen to produce electricity that is stored in the hydrogen car's onboard battery that then supplies power to the motor. The hydrogen car's battery is smaller than ours, but that's just because a car with onboard hydrogen requires a smaller buffer between energy source and the motor than a car like ours that's powered using hydrogen that's in a stationary fuel cell external to the vehicle.