Road Test: Smart Fortwo Cabrio CDI Pulse 2dr Softouch Auto [2010]

We almost drove it off a cliff. Or into a sludgy canal, so only the roof poked through the shopping trolleys and bloated rat corpses. After a week of seesawing gearchanges, earfuls of engine noise and over-firm suspension, we wanted to lose it somewhere dark and unrecoverable.

This updated ForTwo diesel is a tough car to love. So let's start over, with something positive. It is the most efficient production car in the world (discounting sci-fi fuel cells and solar spacemobiles). Like the outgoing version, it has a teeny 0.8-litre, three-cylinder diesel engine that manages a lofty 83mpg. This time around, Smart has released 21 per cent more power, taking the little motor to a whopping 54bhp.

That makes it nippier than the old version, but you still have to deal with the sequential manual 'box, which is like having a learner driver in charge of the clutch. And the throttle appears to be linked to the transmission by goo, making it hard to move small distances without feeling slightly out of control.

All of which is a shame. Smart has freshened up the interior design with some new knobs and instruments, and it still looks cool among iQs and rickshaws. We want to like it, especially with that epic efficiency, but until Smart sorts out those hiccups, we'll be heading for the nearest waterway. At medium speed.