Lexus IS250C in depth

We take an in-depth look at the hits and misses of Lexus' IS250C convertible.

Nothing gets bystanders gawking more than transforming a car from coupe to convertible and back again.

Everything forward of the windscreen is practically shared with the IS250C's sedan sibling, the IS250.

The need to accommodate a folding hard roof in the boot robs the IS250C of the elegance of the sedan.

As with the sedan, the IS250C comes in three grades: Prestige, Sports and Sports Luxury.

Going from coupe to convertible or vice versa takes 21 seconds of quiet brilliance.

The IS250C weighs some 170kg more than its sedan counterpart.

The IS250 sedan misses out on al fresco motoring, as well as LED tail-lights.

The weight gain is thanks to the electric motors required to retract the roof, as well as various structural reinforcements to make up for the lack of a roof.

The extra mass means the engine needs to be worked quite a lot harder, to the detriment of fuel economy.

The IS250C handles sweetly, but the extra weight can be felt in tighter corners.

With the recent demise of the SC430, the IS250C is Lexus' sole convertible option.

The wing mirrors feature LED indicators.

Projector headlamps are standard across the range, but only the top-of-the-range Sports Luxury model has xenon bulbs.

The entry-level Prestige comes fitted with 17-inch alloy wheels, higher specified models get 18-inch ones.

Unlike convertibles from Mercedes, BMW and Audi, there's only one drivetrain choice: a 2.5-litre V6 sending power to the rear wheels via a six-speed automatic transmission.

The interior design is largely lifted from the sedan.

We had no issues looking through the windscreen, but drivers taller than our 165cm may find themselves looking under, at and around the thick windscreen pillars.

Front-seat accommodation is on par with the sedan.

Rear passengers rely on the generosity of those up front for leg room.

Passengers at the back sit almost upright. Shoulder room is restricted as the passenger cell arcs tightly around.

Now you see them...

...now they no longer block the driver's view aft. A simple latch between the two rear seats brings the headrests crashing down.

To stop the rear seat belts flapping about, they can be secured in place by magnetic fasteners.

The plush white leather evoked thoughts of multimillion-dollar mansions with water views.

With the roof up, the boot will swallow 550 litres worth of stuff.

Before the roof can be folded down, the driver must manually set the luggage divider in place. That way the roof won't crush your precious belongings.

Roof down boot capacity shrinks to just over 200 litres.

The double-hinged boot is heavy.

A space-saver spare tyre lives under the boot floor.

The "classy" serif fonts clash with the old-school LCD clock.

Lift or press the centre button to close or open the roof; your finger must be kept there for the entire duration of the process. The button on the left activates a heating element for the windscreen wipers.

The standard rear-parking sensors will call a halt to proceedings if a car or person gets too close to the double-hinged boot.

The car won't stop you from driving away with the roof job half done, but it'll lodge a formal protest.

The reversing camera is accompanied by front- and rear-parking sensors.

Cruise control is easy to operate via this wand, but the singular dashboard light only tells you when the system is on, not whether you've set a cruising speed.

The only engine choice is an eerily silent, incredibly smooth 2.5-litre V6 with 153kW of power and 252Nm of torque.

The gear lever will only let you set a maximum gear for the automatic transmission (fourth gear in this instance).

The standard flappy paddles are a good way of shifting down in a hurry.

Your neck may be cold, but your bum can certainly stay warm.

The front seats electrically tilt and slide forward so rear passengers can enter and alight the car.

The IS250C's instrument cluster features Lexus' bright and clear "optitron" lighting.

The LCD display between the speedo and tacho can display important warning messages, average speed, fuel consumption info, estimated distance to empty and the current gear.

Both the speedo and tacho can be configured to glow a shade of orange if a threshold road or engine speed is breached.

Without any knobs, the standard dual-zone climate control system is difficult to operate by touch alone.

Matters aren't helped by the fact that you need to dive into the touchscreen menus to adjust fan speed or where the air's coming from.

Lexus has fitted an upgraded version of the touchscreen interface to the latest batch of IS250Cs. The look is very reminiscent of the one used in the company's Remote Touch-equipped cars.

Despite the upgrade there's still no 3D perspective.

Lane guidance isn't available, but the system does give you a close view of the upcoming turn.

A six-disc CD changer resides in the dashboard.

Joy of joys, the IS250C comes equipped with an auxiliary jack and an iPod-compatible USB port.

Steering wheel audio controls are easy to use, but there's no mute button.

Bluetooth hands-free works well with the roof up, but voice commands are limited to five phone book voice tags.