I have a ForTwo 451 CDi and yes, despite being the Passion model for softies, it's still really bumpy.
The worst aspect of the road ride though was the instability when driving around 70mph - I was constantly nudging the steering wheel to remain in the motorway lane. However, one day a nail scrapped a rear tyre so did some research on a tyre forum. The ratings there indicated that the factory default Nexen tyres are rubbish. Having taken the ecological and economic "opportunity" to change both rear tyres, I'm happy to say that the ratings were correct and the Pirelli Cintaurato P1 Verde 175/55R15 77H have ransformed this Smart Car into a stable ride at any speed.
