2007 BMW 335i Convertible

BMW could've topped its fourth-generation 3 Series convertible with handsomely tailored five-layer twill fabric like the one it just rolled out on the supercalafragalistic Rolls-Royce Phantom Drophead Coupe. But while the fabulocracy will write a check for a Flying Lady whatever her scarf is made of, the working rich are a whole lot fussier. For them only a tin-top will do these days.

Of course, BMW's breadwinner couldn't wear just any old tin-top. The company's design ethic doesn't include the flying wedges and chin-high beltlines that offer convertible-top designers a convenient place to pile the metal and glass out of sight. No, for the Roundel regulars, the junkin-the-trunk look would never do, and the existing three-piece-roof designs in use on competitors like the Volvo C70 and VW Eos were all deemed too bulky. So the company teamed with its German softtop collaborator Edscha AG to design what it claims is the slimmest-stacking top in the business.

Indeed, the new top not only disappears below a trunk that looks similar to the coupe's, it even preserves 7.4 of the 12.3 cubic feet of trunk space available when the top's up. That slimness exacts a slight aesthetic penalty, however. Two of the rods that guide the front section back over the middle remain in view when the top is closed. They're disguised as a couple of rubstrips running the length of the roof, but it's a less clean look than the competition offers.

The new top mechanism consumes very little rear-seat width, so shoulder and elbow room increases by 3.2 and 4.8 inches, and the side glass is 30 percent larger providing an airier view out. Sparse legroom will elicit grimaces from rear-seat riders over fivefoot-six, however, so vacationers will likely use the back seat for luggage. Toward that end, the rear seatback folds down to form a flat carpeted shelf and preserve the seat leather. BMW even offers a custom-fit bag to fill this space. There is a trunk pass-thru, but it's big enough only for golf clubs and skis, and it can be accessed with the seatback up and the center armrest portion removed. Loading luggage in the trunk with the top down is tricky. Customers opting for the $500 Comfort Access (keyless starting) package can use the key fob to raise the folded top out of the way and load the trunk, but the decklid pivots backward so the gear has to go in over the gunwales. It's far clumsier than the Volvo/Mercedes approach of raising the top stack with the trunk open normally.

Opening and closing the top takes just over 20 seconds and can be done from outside the car with the Comfort Access key fob. Operating the top with the car in motion is verboten for legal reasons (pivoting the trunklid back obscures the license plate). Other convertible highlights include an accessory windscreen that can be installed by one person from the driver's side of the car and leather upholstery treated with an infrared-reflective pigment that can lower the temperature of dark-colored seats by almost 30 degrees. The climate-control system also switches to a top-down mode that redistributes airflow and relies more on the outside-temp and sun sensors than the interior temperature monitors. Safety kit includes pop-up roll-bars and front-seat side airbags with head protection.

Despite the fact that the steel roof and its myriad motors and hydraulics weigh 308 pounds, the finished vehicle weighs just 440 pounds more than the coupe. Credit goes to weight-savers like plastic front fenders and more astute structural reinforcements using varying grades of steel. Torsional rigidity is up 50 percent, and indeed a 335i sport model sampled on smooth Arizona byways felt snare-drum tight, with no dashboard shakes and just an occasional high-frequency vibration following a bump impact with the top up or down. Using the wind blocker, heated seats, and climate-control system, the 3 Series convertible delivers quiet, comfortable, topdown motoring in sunny weather at temps as low as 40 degrees.