I've seen them in person and I've been to the place where they're working it a bunch of times. I'm fairly certain that the reason there was two prototypes is that the first one was moving so slowly that other technology had lapped it, so starting over (to a certain point) was easier than playing catchup. Every time I saw it, it was pretty much unchanged. This one certainly does look better than the first rendition.
Regardless, the whole thing is going really slowly. If I go by where they have their garage this summer, I'll take a peek and see if there's any progress. At this rate, I can't see production any time soon.