In Europe, the Smart roadster is electronically limited at 175 km/h (not 165, but not closer to 200).
This car is really funny, sure. It is like a kart, it is lower than the 914 !
But the main default is about the sequential gearbox: low low and low...
As Mike says, the Smart roadster feeling is extra mainly because of the small 3 cylinders 700cc turbo engine. But when you watch times and numbers, this car cannot be classified as a sport car:
175 km/h maxi
0-100 km/h in 11 sec.
It is the reason why they say it is a toy, not realy a sport car...
Interested ? Here is the UK Smart website
http://www.thesmart.co.uk/