Hi,
Are you
sure that the 1.3L gets better mileage than the 1L? The 1L is about 95HP, so the difference may be in torque.
The iQ has 3+1 seating -- the front passenger can move ahead of the driver, making room behind for the 3rd adult. The child has to sit behind the driver.
It is ~10" longer than the Smart, and they made room by placing the steering and HVAC unit up in the center of the dash, having a very compact transmission and final drive, and the gas tank is under the front seats. There are 9 air bags, including one in the rear window.
It is also wider and lower than the Smart, and it has front wheel drive, which is a great thing, IMO. Weight is ~1,850 pounds. Selling price is supposed to be ~$13.5K, which is reasonable. Five star European crash ratings also are a plus.
Edit: the 1.33L engine will have Start/Stop technology:
http://www.treehugger.com/files/2008...mpg-diesel.php