2010 BMW Z4 Roadster ? Model OverviewThis rear-wheel-drive two-seater?the latest in a long line of BMW roadsters?is now lower and longer than when it made its d?but in 2002. The 2010 BMW Z4 Roadster offers a choice of engines,and features a retractable hardtop as well as a new automatic gearbox. The two-piece aluminum hardtop deploys or stows in 20 seconds,BMW says. The overall length of the car has grown by 5.8 inches since its original iteration,and a one-inch-wider door opening may ease ingress and egress.

To accommodate the roof panels,the trunk has been lengthened,so that it provides 10.9 cu. ft. of storage space with the top up (six cu. ft. with the top stowed). The interior employs BMW?s Sun Reflective leather to protect against heat when the top is down. Leather coverings for the instrument panel,sun visors,and passenger door handle are optional.

An updated version of BMW?s iDrive system is included in the Z4. The Dynamic Drive Control system allows the driver to control throttle response,steering,and stability control thresholds. Various options packages are available,most notably the Sport package,which includes 18- or 19-inch wheels with performance tires,adaptive suspension dampers,and 10-way adjustable sport seats. A recalibrated electronic limiter,which comes with the Sport package,allows a higher top speed.

The rear-wheel-drive 2010 Z4 Roadster is available in base sDrive30i trim,which features a 255-hp 3.0-liter inline six-cylinder engine,or the sDrive 35i,which has a twin-turbocharged direct-injection 300-hp 3.5-liter engine. A six-speed manual transmission is standard and a six-speed automatic is optional. A seven-speed double-clutch automatic transmission is available with the sDrive35i.

The EPA estimates that the sDrive30i will deliver 19 mpg city,28 mpg highway,and 22 mpg combined,with the manual transmission,while the sDrive 35i with manual transmission is estimated at 18 mpg city,25 mpg highway,and 20 mpg combined.

The 2010 BMW Z4 starts at $46,000.