LOS ANGELES – Some fans have been asking for the return of an Infiniti convertible, even though the first one was less than a success for Nissan Motor Co. Ltd.’s luxury division.

That was the Infiniti M30, which had a 3-year run ending in 1992, due to sales so poor it holds the dubious title as the rarest Infiniti ever made.

In a second effort at open-air motoring, Infiniti debuts the sleek and technologically impressive ’09 Infiniti G37 convertible with a 3-piece power retractable hardtop. It goes on sale June 19.

“Our dealers and customers have been asking for a convertible,” says John Weiner, Infiniti’s director-product planning.

If that sounds like the old back-by-popular-demand claim, consider the following.

Two auto journalists at a G37 convertible preview here are driving the new model down La Cienega Blvd. A motorist ahead in a top-down Infiniti M30 slows and waves them up alongside the museum piece he’s driving.

Eyeing the new convertible, he shouts over the din of L.A. traffic: “So they finally took the hint!”

The second coming of an Infiniti convertible has one of the auto maker’s vice presidents, Ben Poore, invoking a deadly sin or two to describe it.

“The Infiniti G convertible instills equal parts lust and envy – lust for its exotically beautiful styling and envy for its unmatched performance credentials,” he says.

Pricing is pending, but with an expected sticker ranging from about $45,000 for a base model to $55,000 for a dressed-up limited Bloomingdale edition, this vehicle is not for the slothful.

The demographic target is people earning $160,000 to $170,000 a year. And while the G37 sedan and coupe have skewed towards male buyers, Infiniti expects a more balanced male-female ownership for the new entry.

With the top up, the convertible looks like a G coupe and shares many of its design traits, such as flowing front fenders, a wave-style aluminum hood and the signature Infiniti double-arch grille.

“From a styling perspective, we think we nailed it,” says John Brancheau, Infiniti’s director-global marketing.

Adds Weiner: “The car is unmistakably a G. It fits in the G family. But it’s not just a G coupe with the roof removed.”

The convertible sports all-new body panels from the A-pillar on back. It is 1.1-in. (2.9 cm) wider overall than the coupe. A wider rear track and a lower rear suspension create room for the “clamshell” roof to tuck into the trunk.

In addition to the standard model, a Sport version of the convertible offers a more aggressive drive ratio.

The car, built in Japan, is powered by a 3.7L VQ-series V-6 featuring VVEL (variable valve event and lift) for improved power, torque and overall engine efficiency. The VQ was a 2008 Ward’s 10 Best Engines winner. It is rated at 325 hp and 267 lb.-ft. (362 Nm) of torque.

Mated to either a 6-speed manual or a 7-speed automatic transmission, the engine has a high level of refinement and the precision of a Swiss clock, whether going flat out on Interstate 405 or climbing Topanga Canyon Drive in the Santa Monica Mountains.

Brancheau contrasts the “warmth” of this car in particular and Infinitis in general with the “machine-like” characteristics of two German luxury brand competitors, BMW and Mercedes-Benz.

He doesn’t mention a third German luxury line, Audi, which more closely resembles Infiniti in feel and performance.

“The G convertible is a car we wanted to do for a long time,” Weiner says. “It seemed like a natural extension of the Infiniti line.”

The car has the look, power and grace of an athlete. But there are the typical downsides and trade-offs of a convertible. Top up, the trunk is big enough to stow two golf bags. Top down, there’s about as much room for a golf glove.

The back seat, while far from voluminous, can double as a storage area for suitcases and such. It can also accommodate humans, compactly and briefly.

“Target-customer feedback showed a need for a backseat, and this one is big enough for an adult to be in it for a short time, say, 30 minutes,” says Weiner. “For our customers, we think top-down beauty and performance will prevail over cargo capacity.”

It takes about 30 seconds to lower or raise the top. That’s about twice the time it takes the Mercedes-Benz SLK convertible to do the same thing. Weiner waves that off, saying, “We’d prefer to beat Mercedes in 0-60 mph (97 km/h) than in top-down speed.”

Early convertibles essentially were coupes with their tops lopped off. The G is designed as a convertible. It’s built on Infiniti’s latest FM platform. Its predecessor platform didn’t lend itself well to a convertible derivative. “So we waited for the second generation,” Weiner says.

It’s a thoroughly modern convertible. A wind deflector reduces interior turbulence, pop-up roll bars enhance safety and special reinforcements eliminate body vibrations often endemic to convertibles.

An innovation is an adaptive climate-control system. It automatically adjusts to blow out cool air if the ambient temperature is higher than 77º F (25º C) and the vehicle is traveling at slow speeds. Conversely, the system sends forth warm air if the temperature is lower than 59º F (15º C) and the car is moving at high speeds.

A Bose sound system, designed for convertibles, has 13 speakers, four of them in the headrests of the front seats. The system uses microphones to automatically optimize equalization settings for open- and closed-top positions.

Infiniti won’t say how many convertibles it expects to sell in this year of the skittish, no-frills consumer.

“Clearly we planned this vehicle and others in a different market environment,” Weiner says. “But I think this segment will hold up well. Also, this is an all-new offering, so we anticipate some pent-up demand.”

Infiniti, now with seven models in its lineup (including the three Gs), sold 147,000 units last year. That is off about 3%, compared with 2007, but not nearly as bad as the double-digit drops other auto makers saw during a disastrous 2008.

Using a tag line, “Inspired Performance,” future Infiniti marketing will focus more on the brand, says Brancheau, a recent hire who spent more than 20 years as a marketer for General Motors Corp.’s Cadillac luxury division.

“We’ll focus less on the individual models and more on the Infiniti brand and how the models align with that,” he tells Ward’s. “It will be subtle, but from a branding standpoint, we’re flipping it.”

sfinlay@wardsauto.com