Interesting you should mention the Versa. That's what My daughter got with my assistance and will retain it's utility for an econimical passenger vehicle. But will struggle as the entry level economic choice for many who are the SECONDARY target group after the AND market like I am. I want a vehicle to keep miles off my Prius and extend it's life. It is also a good way to add life to all those expensive trucks on the road who were purchased for their utility, but widely driven to commute when that utility is not needed.While I too would pay $10k (loaded, out the door) for my Elio, that is because it is on paper the exact vehicle I have been looking for as a companion to my motorcycle for commuting. My "and" vehicle, since we have my wife's SUV for shopping, family hauling, etc.
But if we want it to be an explosive hit, it needs to be much cheaper than what is currently on the market. Smart cars are what I usually compare it to, small car with better gas mileage than a lot of other cars on the road, two person capacity with limited trunk space. And at $14k, looks like they are moving about 10,000 cars per year. Would double the MPG help that? I highly doubt it. But if it were half the price, I think they would be everywhere.
The Nissan Versa, much more practical for most families since it is not an "and" car, has a base MSRP of $11,600. Not the MPG queen the Elio should be, but can carry the spouse, kids, and a dog. Last year, it looks like they sold 144,000 Nissan Versas in the US: http://www.goodcarbadcar.net/2011/01/nissan-versa-sales-figures.html
Assuming the general public can be convinced the Elio is not a death trap, I really think it has to be priced significantly under something like the Versa to make up for the lack of utility. Much more than just $1,600 less.