Mini's marketers are far savvier with their slogan, "Always open." Most everything is unaltered from latest Mini hatchback, including the aluminum 1.6-liter engine making 118 horsepower in the Cooper and 172 horsepower in turbocharged S. Its Detroit show debut highlighted the "Openometer," an extra gauge placed to the left of the tachometer that counts the number of hours you keep the top down, just like Prius owners proudly count lifetime fuel mileage.

Dynamics are close to the hatchback's. The 17-inch Bridgestone Blizzaks needed for Austria in winter highlight the car's torque steer, feeling squirmier in the transitions and when fighting the wheel. More high-strength steel equals a stiffer chassis and 22 fewer pounds for the body-in-white and far less cowl shake than in the last convertible. Manufacturer's 0-to-60-mph time is 0.3 second slower than the S hatchback's. The rear rollover hoop is now a one-piece design that tucks behind the rear seats unless a sensor detects impending rollover, improving rear visibility over the old car's fixed hoops. So the once-standard backup sensor is optional. The rear cowl's chrome trim can pop up with the top up to allow easier access to the tiny trunk. Side glass is larger and Denim Blue is a new, third power-ragtop color option in addition to black and Chocolate Brown.

All this should increase the Convertible's share from 18 percent of Mini sales in the U.S., its number-one market, without cannibalizing hatchback or Clubman sales. It's the quirky route to success.