I'm sure american car companies will rape it and take away all it was intended to do. I'm sure we will have to overpower it. Maybe a 3.5 V6 with 255 horses or something. The best thing to do is leave it alone.
2000 Plymouth Neon
Demand would be a factor as well. For 13-15k people could go for a yaris or perhaps a civic which being a larger car might be more appealing. A little under 5ft wide 8ft long and 5ft high (SMART UK specs) and only seats two isn't going to sell well mainstream. A city only car it has potential, but taking a run through say, San Fransisco you still see more cars then bikes or mopeds...
Why do they do this? Used to be (probably still is) the european performance cars were faster and the european economy cars got better mileage. When they are americanized seems everything falls to the middle average ruining its original design intent. 40mpg? What's the point? Who are these customers? A corolla or civic would be a better choice. I'm a purist, economy cars should get 60mpg or better, performance cars should flatten eyeballs.
Poor people have to save money, rich people LOVE to save money.