The 2010 BMW Z4 is a descendant of the Z3, a pint-sized ragtop best known for its performance as James Bond's car in the movie "Goldeneye." Unlike its forebear, the Z4 isn't a movie star; nonetheless, it's far more qualified to be 007's two-seater of choice. Comprehensively redesigned last year, the second-generation Z4 boasts a retractable hardtop, upscale styling inside and out, a refined ride/handling balance and a pair of superbly smooth and powerful inline-6 engines. Whereas that Z3 was essentially BMW's answer to the elemental but mainstream Mazda Miata, the new Z4 is a world-class luxury roadster that even the most debonair British spy could appreciate.

The first thing you'll notice about the Z4 is its sleekly sculpted sheet metal. This BMW may compete on price with the Mercedes-Benz SLK-Class, but its visual presence evokes the big-buck SL-Class. Like those Mercedes models, the Z4 comes with a retractable hardtop, which sets it apart from both its predecessors and soft-top rivals like the Audi TT and Porsche Boxster. The Z4 has plenty of firepower as well: Even the base sDrive 30i comes with a responsive inline-6 rated at 255 horsepower, while the sDrive35i features a 300-hp twin-turbocharged inline-6 that produces a 0-60-mph sprint of just 5.2 seconds. The sDrive35i is also eligible for BMW's seven-speed dual-clutch automated manual transmission (it also appears on the high-performance M3), while the sDrive 30i makes do with a conventional six-speed automatic.

Enthusiasts will no doubt mourn the passing of the old M Roadster, a hard-core, M3-engined version of the previous Z4. Even the turbocharged sDrive35i is down 30 hp by comparison, and it has none of the M Roadster's edginess when driven hard. However, the latest Z4 greatly expands upon that car's niche appeal, nearly matching its on-paper performance while slathering on thick layers of style, luxury and versatility. Those in search of maximal thrills may want to look elsewhere, but the Z4 is plenty capable for most tastes, and adds a level of sophistication that few small convertibles can match.

Consequently, the Z4's competition is all over the map. The aforementioned Mercedes-Benz SLK-Class remains a viable contender, but it looks and feels less special; as noted, the Z4 may be closer in spirit to the SL-Class, which commands twice the BMW's price. Porsche's Boxster ragtop and Cayman coupe are significantly more engaging to drive, and Chevrolet's Corvette convertible delivers big V8 power, but they can't match the versatility of the Z4's retractable hardtop. The Audi TT and Nissan 370Z convertibles are cheaper, but they're also less car. W.W.B.D. (What Would Bond Drive)? Quite possibly the 2010 BMW Z4.

The 2010 BMW Z4 is a two-seat roadster with a retractable hardtop, available in either base sDrive30i or more powerful sDrive35i trim. The main distinction between the two cars is in the engine bay, but standard equipment also differs.

The base sDrive30i model includes 17-inch wheels, xenon headlamps, heated outside mirrors and rear window, a leather-wrapped multifunction steering wheel, premium leatherette vinyl upholstery, six-way manually adjustable seats and a CD audio system with HD radio, satellite radio preparation and an auxiliary audio jack. The sDrive30i also comes standard with driver-adjustable steering, throttle and -- if applicable -- automatic transmission programming. Going with the sDrive35i gets you a more powerful engine and a few extra features like sun-reflective leather seating, automatic climate control and brushed aluminum interior trim.

There are several notable option packages. The Premium package includes leather and automatic climate control for the 30i model, power seats with driver-side memory settings, an auto-dimming rearview mirror, ambient lighting, Bluetooth and BMW Assist. The Cold Weather package includes headlight washers, a heated steering wheel, heated seats and a ski bag pass-through from the trunk. The Premium Sound package includes a 14-speaker surround-sound audio system with a six-CD/DVD changer and an iPod/USB jack. An Ivory White Leather package gives you exactly what it sounds like and also includes special wood trim and 10-way-adjustable manual sport seats. Finally, the Sport package includes 18-inch wheels with performance tires (19s are available at extra cost), adaptive suspension dampers, the aforementioned sport seats and a higher top speed thanks to a recalibrated electronic limiter.

Many of these options are available separately, but a few stand-alone options that are not included in packages are keyless ignition/entry, a hard-drive-based navigation system with iDrive, a pop-up screen and digital music storage, parking sensors and automatic high beams.

The rear-wheel-drive 2010 BMW Z4 offers two engines -- one for each trim level. The base sDrive30i comes with a naturally aspirated 3.0-liter inline-6 that makes 255 hp and 220 pound-feet of torque. The sDrive35i receives BMW's twin-turbocharged inline-6 that's rated at 300 hp and 300 lb-ft of torque. Both cars come standard with a six-speed manual transmission. A six-speed conventional automatic is optional on the sDrive30i, while the optional transmission for the sDrive35i is a seven-speed dual-clutch automated manual.

In performance testing, we clocked the sDrive35i from zero to 60 in 5.2 seconds with the six-speed manual. EPA fuel economy estimates range from 19 mpg city/28 mpg highway and 22 mpg combined for the sDrive30i (19/29/22 with the automatic) to 18/25/20 for the sDrive35i (17/24/20 with the automated manual).

Side impact airbags, antilock brakes with brake assist, and stability control are all standard on the 2010 BMW Z4. The antilock brakes also integrate several features designed to improve braking performance, such as periodically wiping the brake rotors dry when the windshield wipers are in use and automatically snugging the pads to the rotors if the driver abruptly lifts off the throttle.

The roof is made of aluminum and incorporates a structural support system that helps protect occupants in case of a rollover accident. To provide protection in the event of a top-down rollover, there is a steel hoop behind each seat.

Even the base 2010 BMW Z4 sDrive30i is an entertaining drive thanks to its willing and exceptionally smooth 255-hp inline-6. The twin-turbocharged sDrive35i is better yet, offering up authoritative yet ultra-refined acceleration. One of our editors described the exhaust note as "flatulent," but others appreciate its distinctive character. The sDrive35i's dual-clutch automated manual transmission delivers quick and smooth shifts in Manual mode, yet it also does a very credible impression of a conventional automatic.

When driven aggressively, the Z4's limits are high, but its reflexes and communication with the driver are somewhat lackluster. The culprits here are a numb electric power steering system and the Z4's stubborn understeer in hard cornering. Nonetheless, a Z4 sDrive35i with the Sport package should provide enough sporting entertainment to satisfy the majority of luxury roadster buyers.

The 2010 BMW's Z4's cabin is sleek and upscale. High-quality materials abound and combine with diverse shapes to create an undeniably premium environment. Thankfully, BMW didn't forget about practicality along the way. There's a small storage area behind the seats that works well for purses or backpacks, as well as a moderately sized pass-through that effectively expands trunk space to accommodate long items like skis or golf clubs. The iDrive vehicle interface has been vastly improved -- it's now arguably the best of its breed, with an intuitive menu structure and helpful physical buttons alongside the familiar circular controller.

The hardtop does eat into storage space when folded -- there's a respectable 11 cubic feet with the top up, but only 6 with the top down. The folding top is power-operated and takes about 20 seconds to retract.