I disagree it was a "joke"; I'd say it was a concept car - their vision of the future. They need steering wheels because they're still testing them, but the Firefly is the goal.
they made a few then had to install wheels after it was pointed out it was illegal in CA to drive without them- IE, lack of basic due diligence. And they've reverted to conventional cars as a platform because that makes more economic sense. Fine to have a goal but if you never get there and make basic bungles on the way, it's a joke.