Damned by Statistics
You have to bear in mind what this vehicles speciality is and then you can understand it better. its not a motorway cruiser its really a stop start city car. and the economy figures really fail to do justice to this car.
My journey to work is 6 miles through the middle of a city centre I drop the misses off at mile 5, it usually takes me 20 minutes at an average of about 18mph, I pass no less that 30 sets of traffic lights an usually stop at at least 10 of them. I drive a 2 litre turbo diesel and can get anywhere from 34-24 mpg depending on the number of stops (its a hilly city too!). I see this car in a slightly different light, as it is able to recover energy from coasting to a stop at lights and then use that to launch back up to criusing speed again, effectivly cutting the fuel consumption dramatically, I see my situation as ideal for this kind of vehicle and would expect the most dramatic efficiency savings from this type of car, yes others are better at motorway cruising on just oil, but I dont do that often!
However I would really like to see this car taken further, at least double the motor power and double the battery capacity, taking it a lot closer to the prius spec but still a small car. or even better quadruple the motor and battery in a plugin vairant!
And before anyone suggests it, public transport is Crap! I can walk 10 minutes to a bus stop get a bus into the city (15 mins) then I need to walk across the city centre, 15-20 mins, and get another bus (15 Mins) out the other side which goes to a housing estate not the commercial park. so I then have another walk (15 Min) total time well over 1 hour, 2 miles on foot, and all for £3.20! no thanks!!! So I car pool with the missues, and save half the time! (time is the luxury you cant buy!)