Italian with a sexy swagger

Maserati's GranCabrio looks a picture with the soft-top up or down. Leg room is a highlight of the tidy interior. Photo / Supplied

Maserati says 62.5 per cent of the world's population will sit comfortably in the rear of the GranCabrio, the luxury Italian carmaker's first in-house convertible.

It knows this because a computer told it so. Maserati fed the dimensions of the car's rear seats into a computer and software figured it out using, says Maserati public relations man Edward Rowe, a "bell curve distribution of body size".

The computer had been playing with random numbers and already knew that two-thirds of the world's population were of such-and-such size. Therefore, most of the world's Bobs, Carols, Teds and Alices would fit into the car's back seats.

Maserati could have gone further, of course. Like asking the computer what percentage of the 62.5 per cent had an IQ of over 120, for example. Next question: would the back seat be more appealing to those with a high IQ, or those with a middle ranking?

The computer itself would have gone on forever, fed with a diet of digital data. Bit like arguments over the theme of the 1994 book The Bell Curve. Its authors reckon natural intelligence is the best crystal ball of all. A better pointer to future success than the advantages of a wealthy background, or education. Something like that anyway. Others disagreed.

Using the book's theory, Maserati could perhaps claim that young men and women with middle-of-the-road IQs are more likely to get up to hijinks in the back seat of the GranCabrio that those with high IQs.

On the other hand, it might have to factor in exceptions, that the best and the brightest of Maserati owners might indeed be seduced by the car's toplessness and get a bit reckless.

Whatever, Maserati didn't go that far - unlike Volkswagen. The German carmaker fiddled with a bell curve and found that upwards of 15 million couples have had sex in hatchback Golf models since the first was launched 36 years ago.

It said, too, that 12 million children had fallen asleep on the seats of the car over the years. It didn't say how many of the 12 million kids were conceived by the 15 million couples. Its research didn't go nearly as far as the couples did.

Maserati, meantime, doesn't care what goes on in the GranCabrio's back seat, only that there is room enough for two. The new soft-top is the Italian carmaker's first. Its past convertibles, elegant designs carrying the Trident badge going back to the AG6 Frau Spyder in 1950, the 3500GT Vignale of 1959, and later the Mistral Spyder, were built by specialist coachbuilders.

The GranCabrio is about to go on sale in New Zealand, priced from $338,000. It was launched the other day on roads on Australia's east coast, in unseasonally cold weather.

The soft-top is based on the GranTurismo. It is a soft-top, too, a triple-skinned 65kg canvas contraption that electronically folds into the bodyshell ahead of the rear boot. A folding tin-top would have weighed too much and compromised handling dynamics. Besides, the Italians reckon canvas is more romantic. Especially in a choice of six colours.

The roof can be opened or shut in 28 seconds on the move, or below 30km/h. The car's top speed with the roof up is 283km/h; or 274km/h with it down. Distribution across its 1980kg kerb weight changes too: 51 per cent rear, 49 front with the roof in place; 52:48 with it down.

The GranCabrio is based largely on the GranTurismo coupe but is about 100kg heavier. Most of the extra weight comes under the skin, in the form of strengthening to the body to reinforce torsional rigidity, or to reduce body flexing inherent in a soft-top, especially one with the longest wheelbase in its class.

It's the shoebox theory: take the lid off a shoebox and it twists every which way. Leave it on and the shoebox resists twisting forces.

The GranCabrio is indeed a long car, longer even than the topless Bentley Continental. But it disguises its 4.9-metre overall length as well as any of its luxury rivals and looks a picture with the top up or down.

Highlight of the tidy interior is leg room, both front and rear. Headroom at the rear with the top up is tight, mostly because the rear seats are slightly higher than those in the front.

The main downside for such a long car is the boot. A chassis reinforcing wall intrudes to cut it back to 170-odd litres. Pack golf clubs and a suitcase or two and the back seat comes into play as a luggage rack of sorts, reducing the GranCabrio to a two-and-a-half seater.

Not that Glen Sealey, general manager of Maserati Australia and New Zealand, would agree. "The GranCabrio is much more than a convertible version of an existing model in the range," he says.

"Its broad range of attributes as well its ability to excel in all the traditional requirements of a convertible mean that sales will not only be predominantly to new customers for Maserati, but will also further enhance the image and reputation of the brand.

"For these reasons we expect the GranCabrio to substantially add to Maserati's sales total in both Australia and New Zealand."

The car is powered by a 4.7-litre V8 driving the rear wheels via a six-speed ZF automatic gearbox with manual mode and mechanical limited-slip differential. The engine delivers 323kW at a maximum 7000rpm and 490Nm of torque at 4750rpm. Expect a best town-and-around fuel usage of around 12-13 litres/100km and a worst of 17.

Suspension is made up of double wishbones at the front and rear, with steel springs and anti-roll bars. Maserati's Skyhook adaptive shock-absorbers are standard. Skyhook uses speed readings taken from sensors on each wheel and the body to continuously adjust the valve in each shock.

A Sport button, which adjusts the suspension mapping to trade ride comfort for improved body control, also quickens the gearshift and opens the exhaust flaps beyond 3000rpm.

Stir the car along high in the torque range in Sport and manual mode and it is not as soft as it looks. It remains lively on its adaptable suspension, anchored through the twists and turns as well as a soft-top of that length can be, its delightful exhaust note trailing behind.

There's very little wrong with the helm, either, although purists would want more accuracy. Brakes are especially good.

But in standard automatic torque drops away noticeably at between 2000-3000rpm and it loses mid-range oomph, becoming more of a Gold Coast cruiser.

It is not a hard-out driver's car, unlike others with the Trident badge. It's a compromise, after all, a hard-top turned into a soft-top. That said, it remains an impressive four-seater, charming and sexy all at once, in an Italian kind of way.