By Tim Plouff

But car buyers don’t often listen to the critics, as sales of Bangle-designed BMW’s are higher than each of the models that they replaced except one. (And that decline is due to market forces, not the car’s look.)

Critiques from the peanut-heads have brought more attention to the brand — market awareness that has led to wider acceptance and increased sales. How could you not enjoy that kind of success?

Perhaps the most radical of Bangle’s efforts is the sassy Z4 convertible pictured here. Three years ago, the larger Z4 replaced the initial small sports car, the Z3, a popular German interpretation of the Mazda Miata. The Z3 was an immediate hit, its voluptuous lines attracting new customers to the roundel brand. BMW built three different versions, with ever-increasing power, and then authored a muscular copy called the Z8 for the high-dollar, high-performance crowd.

Despite the Z3’s success, many BMW insiders felt that the Z3 was too much of a “chick-car” even though 65 percent of sales went to men. The redesign would need to be more masculine to better compete with new rivals from Mercedes and Porsche.

The sharp creases and distinct lines of the Z4 certainly indicate a taut, strong body that will never be confused with the rounded lines of the Audi TT. While the appeal for the Z4 remains strong, its overall sales have lagged behind the Z3 for two reasons. The sports car market has several more competitors than it did when the Z3 debuted and BMW won’t roll out the high-powered M version of the Z4 until this fall, a good three years after the Z4 started production in South Carolina.

My sample Z4 was the base 2.5i equipped with several options: five-speed automatic, power top and sport suspension. Metropolitan markets dominate the sales charts and clogged streets and parking lot freeways have relegated the leg-stretching clutch manipulation of a manual transmission passé in these markets. Manual transmissions now appear in less than 10 percent of all new cars, including sports cars such as the Z4.

That’s a shame, as a whole generation of drivers cannot master the synchronization of throttle foot, engine revs, shift lever hand and a clutch pedal. A whole driving segment cannot revel in the thrill of gracefully mastering the intimate interaction between man and machine while maximizing the excitement provided by this skill.

My left leg instinctively reached for a non-existent clutch pedal during the whole week of the BMW’s visit, just as my right hand tried to upshift the automatic lever into a third gear that would have produced a grinding of gears like no other. The persona of the car demanded a manual transmission but the engineers have created an alternative that works reasonably well.

The manual-shift mode of the slick automatic is your alternative, your path to interaction with the car’s performance. Either mode executes excellent shifts, up or down, and the free-spirited, in-line six engine never protests the use or abuse. BMW claims the automatic delivers virtually the same accelerative prowess as the manual-equipped versions, so Z4 owners suffer no lack of peak performance — just the added thrill of a real stick, and $1,200.

The Z3 started life with a 1.9-liter, four-cylinder engine — a powertrain that made it faster than a Miata but it didn’t exactly flatten your eyeballs.

The Z4’s base engine spins out 184 hp and again reinforces the impression that BMW’s motors are over-achievers. The claimed horsepower rating seems low to the car’s actual performance. Low-end grunt is slow to develop but once the tachometer spins past 3,000 rpm’s, serious action occurs. The standard traction control eliminates wheel spin while the anti-skid system supports your elevated pace with an appropriate safety net. Steering feel is linear — precise, crisp and responsive while the turning radius is minuscule.

The ride is sports car firm, maybe a bit too firm with the optional sport suspension for some of our seasonally ravaged secondary roads. Very little suspension travel combined with hard, low profile 17-inch Bridgestone Potenza, run-flat tires made the Z4 more than a little jittery when the pavement presented less than perfect conditions. Thankfully, the Z4’s body is among the most rigid of all convertibles, so cowl shake was non-existent.

Roll across fresher conditions and the Z4 is a delight. Negligible body lean and right-now response to your input make this roadster a comfortable sports car companion.

Most of the allure of this package is not its 9/10ths extreme handling anyway, but the pleasures that it delivers when you lower the soft top. This is when the Z4 really shines.

Equipped with the optional power top ($750) the Z4’s roof lowered in less than 10 seconds. Visibility instantly improves over the somewhat claustrophobic cabin with the top up, and your spirit soars. Wind buffeting is minimal, even at highway speeds.

With the top lowered, the Z4’s angular lines and complex shapes seem just right. The car is perfectly balanced — 50/50 weight distribution front to rear — even with the traditional long hood, short rear deck design.

The Z4 is more fun to drive than a Miata because it has more power on tap — a lot more useable power. The price discrepancy between the two may deter many buyers from making a new car decision for the BMW, but when compared to the Porsche Boxster or Mercedes SLK, the Z4 is a bargain. The Z4 continues to outsell each of these premium rivals despite newer versions.

The Z4 had some of the best headlamps I’ve ever driven behind. The bi-xenon lights turn night into day with a large, brilliantly illuminated white field of vision when the high-beam lamps are on. To me, this is just as important a safety feature as ABS brakes or the anti-skid system. I would however prefer less restraint from the pre-tensioning seatbelts. If you quickly lean forward to see out the starboard side window, the belt fetches you up hard and restricts your movement in an untimely manner.

With the M version returning this fall, the Z4 lineup will again be complete. A sleeker looking coupe than the previous Z3 rendition, the new Z4 offers a 340-hp 3.2-liter six and should easily match Porsche’s new Cayman sports coupe.

In the competitive and entertaining sports car segment, the small Z4 is still a winner, a slick unconventional two-seater that turns heads and pleases the heart.