Parkers overall rating: 3 out of 5 3.0

Only one engine is available in the IS 250C - and as the name suggests it's a 2.5-litre. The 205bhp V6 is the same engine that's used in the IS saloon but is available exclusively with a six-speed automatic gearbox that includes paddle controls on the steering wheel. The engine itself is very smooth and quiet, adding to the refined feel of the IS 250C, but it lacks pulling power and isn't responsive from low down.

0-62mph takes a respectable 9.0 seconds - but that's actually slower than the standard four door IS250 automatic, while economy is a fairly poor 30mpg. The engine and gearbox combination do make for effortless motorway progress, but there's little fun to be had at other times. You often have to force it to change down to get decent acceleration and even then it's not very swift.

At high revs the engine becomes pretty noisy and sounds quite coarse too.

Lexus is open about the fact the IS 250C is designed for refinement rather than keen driving. With the roof down, the body doesn't flex - a problem that can afflict some convertibles - and it rides well over potholes and bumpy roads. However, push it into a corners and the lack of driver appeal is immediately evident. It doesn't have the nimble feeling of other hard-top convertibles like the BMW 3-Series and feels heavy in comparison.

Despite extra body stiffening compared to the saloon, there's too much body roll in corners and the artificial feel of the electric power steering means it's not an especially enjoyable car to drive. It's far happier gently cruising along straight roads.