BMW got the technology just right in its new 3 Series convertible: With the top down, you can actually read the navigation system's information. If you come back from the beach and left the top down, the infrared-reflecting leather doesn't scald your bare legs. When you drive, the wind whistles by but doesn't muss your hair, and you can talk without shouting. Life is good in a BMW.

Just out, this is BMW's first foray into hardtop convertibles: Rather than a fabric top, three metal roof sections come out of the trunk on motorized arms and, 23 seconds later, form a weather-tight, noise-muting cocoon overhead.

Retracting takes 22 seconds (no, we don't know how the extra second was saved). The order of the retracting roof sandwich is rear panel on top, front in the middle, middle on the bottom. And it is most cool to watch. It will attract and stop in their tracks just-passing-by mechanical engineers, and quite possibly good-looking members of the opposite sex.

A metal hardtop adds 50 to 75 pounds of weight compared to a fabric convertible top, and that's on top of the heavy stiffeners and braces most convertibles need to reduce cowl shake--the feeling that the body is twisting and the left and right sides of the car are tracking slightly different courses over bumpy roads. All told, the BMW 335i weighs 452 pounds more than the 335i coupe from which it's derived, 4,023 pounds total.

All that extra poundage means you really want the twin-turbo 335i rather than the non-turbo 328i convertible, even though it's an extra $3,500 (comparably equipped). As I found when previously driving the BMW 335i turbo coupe, no matter what the EPA ratings say, you get either 10 mpg when you're having too much fun, or 30 mph when you're a sensible citizen and don't flog the throttle.

There is very little fuel-economy penalty when you drive the two cars comparably. But you are driving with premium fuel—although, if you just forked over fifty grand for a bauble like this, you shouldn't be complaining about the extra 20 cents a gallon for premium.

It's a BMW, so the car drives fine. The extra 452 pounds compared to the coupe make it a bit slower but still quick. I noticed only the slightest amount of what felt like cowl shake, better than any other convertible.

It's with the top down that this BMW shines. By using a transflective display in the dash, you can read the navigation system, which includes real-time traffic, even when you're wearing dark sunglasses.

A transflective display has a backlight, but during the daytime the primary illumination comes from ambient light. More light, more brightness. It adds a couple dollars to the cost of each navigation-system car, and while that seems a non-issue on a high-end vehicle, automakers sometimes cut corners where they shouldn't. I'm convinced every convertible or car with a big sunroof ought to have a transflective LCD.

Most BMWs come with leather upholstery (vinyl is the default, but you'd be hard pressed to find one so equipped), and cloth isn't an option. If you order the Dakota leather (a BMW term) on the convertible, it gets the protective IR-blocker coating as part of the deal.

With a metal-roof car, IR blocking isn't such a big deal, unless you leave the windows open and the sun shines directly on seats on one side.

This convertible spent hundreds of hours in a wind tunnel to make airflow over the open cockpit more perfect. You feel the sensation of wind around you, but your hair doesn't fly about, especially if you raise a backseat sunscreen. At highway speeds, I had no trouble talking with a passenger so long as I spoke with a bit more volume than I usually do. And that's with a car that exposes the occupants' shoulders and head above the car's so-called shoulder line (where the side windows meet the body). The reason? When people outside look at the occupants of a convertible, says BMW body shell designer Michael Brachvogel, they find the car visually awkward if they see only the heads.

Most occupants of a convertible find the wind-whipping-through-your-hair routine gets old in a hurry, especially if it happens at 35 mph when you're tooling about town. I found no need to roll up the windows in city/suburban driving and only after an hour on the highway did we agree it would be slightly more pleasant to drive with the windows up (and the top still in the trunk). The biggest problem, especially in the city, was getting used to road noise from all the other cars and especially trucks around you. Either you learn to live with urban vibrancy, or you put the top up.

One glitch: BMW's turn signals work differently from other cars. The indicator lights are obscured by the steering wheel, and the barely audible clicker can't be heard when the top is down.

BMW uses what's called mechatronic switchgear. You push the lever all the way up or down to engage your turn signal, but then the lever pops back to the neutral position. To cancel, you push in the same, direction— not opposite. Push it halfway up, let go, and you get three blinks. Every time, it returns to center. Eventually you'll get used to the methodology, but between that and the obscured indicator lights, you won't be happy.

The folding top takes up most of the trunk, leaving space for one medium-size suitcase (7.4 cubic feet). No problem: The back of the back seat folds down and forms a skid-resistant loading platform, providing enough space for most couples for the weekend. You can maximize carrying by buying a fitted three-piece set of luggage for the back seat.

If you're carrying people in back (not cargo), it's a bit more compact than a 3 Series hardtop, but with more room (and larger window glass in back and on the sides) than you'd get with a fabric-roof convertible.

You'll probably want to order the optional pass-through, which is the best way to carry golf clubs—or skis, for that matter. While the seatbacks fold down, a structural bulkhead remains, except for the pass-though. That's part of the stiffening needed to keep the convertible stable.

This car continues BMW's new tradition of having a separate Start button regardless of whether you have a traditional key that has to be inserted in the dash or keyless go. Unlike on most other non-3 Series BMWs, iDrive is installed only if you get navigation. Navigation is expensive at $2,100 but includes lifetime real-time traffic updates from Clear Channel and Inrix, and the brilliant LCD.

You can also order adaptive cruise control, HD Radio, a sport package, and a second-generation music adapter that uses a USB jack, which lets you connect any music player or music on a memory key, not just an Apple iPod. But this wealth of options can add $13,000 to the base price.

BMW's website is easy to navigate. The build-your-own section is especially graphical, with images of each option, and that's a problem: BMW's layout shows only some of the options at one time, and it's easy to miss a couple. There's also an area for owners (Owners' Circle) but it's heavy on marketing material. One exception is a click button to send a priority e-mail (not just e-mail); it gets you a thoughtful response to nearly any question, usually on the same day.

Convertible buyers represent a small slice of the market and typically have a different mindset than buyers of hardtop coupes (though not sedans). The biggest markets are around Miami and in the Los Angeles/Orange County areas.

But there's no question about it: A $50,000 to $55,000 convertible is a luxury, not a necessity. If you're looking for a modicum of practicality in a nobody-needs-this kind of car, the 3 Series convertible makes a good deal of sense, especially since BMW has solved problems that bedeviled previous generations of convertible owners. It looks great, runs fine, and there's a place for your skis and golf clubs.

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$49,875.00 - $63,570.00

EPA rating: 20 mpg city, 29 highway

BMW implemented technologies that really benefit topless driving. But you'll curse the turn signals. Go with the twin-turbo 335i, which gets essentially the same mileage as the non-turbo 328i.

Transflective LCD gets brighter in strong sunlight. Sun-reflecting upholstery for cooler seats. Relatively quiet with top down. Ultra-cool motorized hardtop.

Turn signal doesn't function well with the top down. Even the cheaper 328i costs $50,000, typically equipped.