They don't rewrite these all from scratch. The 10-K says "the design and manufacture of a production prototype will be completed in the third quarter of 2017." Prior to this, expected delivery per the company was asserted to be by July 2017 which, at the very least, is in the 3rd quarter.
Agree. Underwhelming . It's always one step forward- two back, or so it seems. One thing you need to stay long is a patience and acceptance that, more often than not, while they'll state they're on course, but still rarely , if ever hit hit stated timelines....