Disclaimer: The following is pure conjecture and opinion. I'm no automotive insider. I'm far from it. So FWIW....
As a consumer, I hate the Empulse experience. When I remove my emotional connection to the product, however, I completely understand. Detroit typically doesn't make promises about deliveries until they're well into production. Automotive manufacturers are very scientific about their process: think "The Toyota Way." Their development processes have been templated and translated to many other industries and not just manufacturing. They do intense market and feasibility studies well before a prototype even hits a car show show. It's not perfect, and Aztecs still happen every decade or so.
Detroit always has many projects in development as well, so they have a prototype that's not testing well, they can easily cancel it and another project already underway slips right into its spot. Brammo and Tesla don't have that luxury. They have to keep everyone on the line: Wall Street, bloggers, politicians, and consumers. Why? They need the buzz to stay afloat long enough to... to change the world. They can't rely on current sales to keep them running. They can't dig deep into R&D and find something to sell this year. They can't rely on Craig and Elon's money.
If they weren't American companies I wouldn't trust them nearly as much. The only reason that I have faith in Brammo, is that that I feel somewhat know them personally. It would behoove them to try to communicate more openly with their customers to ensure that their genuineness comes through. Alas, their hands are somewhat tied. They've got Wall Street, bloggers, politicians, and investors all listening now too. I'm sure Adrian would love to make things a lot more transparent, but they just can't. Hell, let's just consider ourselves lucky that they're not a publicly traded company yet. Meeting analysts expectations is the single biggest waste of time, energy, capital, and talent for so many companies.