(Business 2.0) – When last I checked, the "Stop Chris Bangle" petition had 4,206 signatures. "The undersigned thank you, BMW, for creating our dream cars," it reads. "Please continue doing so, fire Chris Bangle, and DO NOT allow him to design (ruin) any more of your wonderful BMWs." There is also a German edition of the petition--"Stoppt Chris Bangle!"--which is a tad less genteel: "Der Mann ist verruckt! Feuert ihn sofort!"

Ordinarily none of this would concern me much, since I know neither Chris Bangle nor any actual Germans. But as it happened, occupying my driveway at the moment was a sterling-gray 2003 BMW Z4 roadster, the very burr irritating this global cadre of signatories--as well as a significant number of car-industry critics, professional and amateur. And basically, they believe the car looks like scheisse, as a German might say.

Just listen: "The Z4 is a joyless, fish-mouthed jumble," wrote Mickey Kaus on Slate. "The Z4 has derriere issues," said the New York Times. "Plain goofy-looking," offered a critic from Automobile. So who to blame? Responsibility, they suggest, must be laid at the feet of Bangle, a 46-year-old American who now finds himself director of design for the BMW Group and thus the person most credited (or condemned) for the radical look of the Z4. After reading some of the notices, I phoned Bangle. He had a Continental accent and was exceedingly polite. "Well, yes, we've left some people standing by the by," he said, referring to the Z4's critics. "And maybe that isn't the wrong thing to do." If you were very, very quiet, you could just make out "Losers" echoing in the air.

Before we proceed, however, let me note that virtually every arrow slung at the Z4 has to do with its appearance. Few critics find fault with how the car is put together (which is immaculately) or how it drives (which is wonderfully). Now, creating a good roadster is one of those things that, like bigamy, sound simple in the abstract but are almost impossible to pull off successfully. Make one little slip and you might end up in jail--or with a Chrysler LeBaron. If the car's weight distribution is anything less than perfect, the front end will plow or the tail will wallow, and the drive will feel like mush. Skimp on frame rigidity--always an issue with convertibles--and the roadster will pitch and yaw like a rubber raft. Neglect one little detail of aerodynamics and whistling vectors of wind will knife through the cockpit, or drag along the windshield line, or buffet the ragtop until the tortured driver is made partially deaf and wholly insane.

But since BMW is arguably the most technologically adept automaker, it was able to meet such challenges with relative ease: The Z4 has an almost perfect 50.4 to 49.6 front-to-rear weight distribution; it is nearly twice as rigid as the car it replaces (the still-popular Z3); and a massive amount of computer-aided design work managed to trim the Z4's drag coefficient to a slippery 0.35, while also making certain that the cockpit would remain free of gale-force winds. Although BMW does suggest using the accessory windscreen when you exceed 100 mph in the car. Hypothetically, of course.

The Z4 is also BMW's first model to incorporate electric power steering, which replaces that nasty and inefficient hydraulic system with one that gathers data from sensors in each wheel, calculates vehicle speed, and adjusts the amount of resistance applied to steering accordingly--less when you have slowed in order to parallel-park, for instance, and more when you're screaming along at a hypothetical 100 mph and thus want slightly less touchy highway driving. BMW has also married this system with the Z4's Dynamic Driving Control, which with the touch of a button on the shift console reprograms the Z4 for sport mode by firming the steering, quickening the electronic throttle, and, in models with automatic transmission or the soon-to-be-released sequential mechanical gearbox (which does away with the clutch pedal), altering the programming to shift up an instant later and down an instant sooner.

What all this mechanical minutia really means, though, is that you can goose the car at will and whim, and the Z4 will happily comply. I spent a few days with the Z4 in the Marin Headlands, on the loopy twists that rise and fall alongside the Golden Gate, circuiting the headland roads, juicing the car up inclines, hustling it around hairpins, stomping it to a crawl as packs of triathletes cycled by on their training rides. Never once did the car get squirrelly or lag, and seldom did it fail to turn heads.

This latter response happens to be the thing Bangle is most obsessed with these days, ever since BMW plopped the design gauntlet for its cars into his lap and bade him to boost sales in the United States by 50 percent. To do this, Bangle has completely reimagined the BMW line, and the Z4 is the second official output from his atelier, after the controversial 7-Series. Although Bangle can sound comically overwrought in describing his approach (he recently called the Z4's radical design leap "as big a jump in terms of aesthetic value systems as there was between an Eve before the fall...and an Eve after the fall"), the cars he is producing are arrestingly unique. Which, of course, bothers at least 4,206 people--one of whom, in fact, has taken it upon himself to improve, via Photoshop, Bangle's designs. (If you're interested, you can find the before and after photos at slate.msn.com/id/2076313/.)

Me, I'm in the pro-Bangle camp. Though mechanically the Z4 has been executed well enough to rank among the best roadsters even if it looked like a refugee from the soapbox derby, the addition of the car's cascade of hard concave and soft convex lines only makes it better. BMW--or, actually, Bangle--calls all these metal scoops and bulges and curlicues "flame surfacing"; the notion is to have a car that appears to be moving even when parked. And, in fact, it does. On my excursions, the shifting fog and clouds off the Pacific caused the Z4's flanks to ripple and tense, even when I was doing nothing more dynamic than idling at the tollbooth fishing out money for the ride back across the Golden Gate Bridge.

"Hey, what is that thing?" the toll taker asked as I handed over my five bucks.

"The new BMW," I said. "What do you think?"

He leaned out the window and stared. "Well," he said finally, "it's kinda weird-looking."

Everyone's a critic.

John Tayman is a contributing writer for Business 2.0.