2004 BMW 645Ci Convertible

BMW's recently launched 645Ci coupe is just now arriving at dealerships, yet the company didn't waste a minute in introducing the convertible version. They were, of course, designed at the same time, so the ragtop is no mere chop job. Although there's some discernible relationship between this latest coupe and the last-generation 8 and 6 Series, we need to reach back to 1965 to make a convertible connection. It's a slim one at that, as BMW built just a single ragtop version of its Bertone-designed 3200CS coupe.

So it's fair to say that the 645Ci Convertible is the first two-plus-two, V-8-powered top-downer from BMW in almost 40 years.

With the top up, the convertible shares the organic profile of the coupe we tested earlier this year (January 2004). Yet, lower the crown and suddenly the graceful body lines meet in a tasteful shape that's all its own.

Center console features updated iDrive controller, removable cupholder, and sweet-shifting six-speed. Back-seat hairdos are protected by glass diffusers.

Luckily, BMW had the foresight not to incorporate the top's operation into the car's overly complicated iDrive system; the fully lined top is power-operated by a console-mounted button, lowering in 24 seconds. This rather trick lid is windowless, allowing the designers to integrate the glass into the rear deck, directly aft the headrests and completely independent of the top so the vertical window can be deployed as a wind deflector when the top is down, or, with top up, the glass can be lowered to increase pass-through ventilation for the cabin. Rear window operation is controlled from the driver's door-mounted switches, which can be programmed to lower or raise all five windows simultaneously using a single switch.

Though roof removal will always result in a loss of structural rigidity, we were hard-pressed to detect much more than slight cowl shake during our test. Only the deepest potholes and tallest speed bumps could shudder this ultrastiff chassis. BMW claims the additional reinforcement throughout the vehicle's structure results in slightly more stiffness than in a 645Ci coupe with all its windows rolled down.