The cost: About $22,000 to start
The top: The Mini Cooper's power-operated convertible top can be used in three different positions: all the way up and all the way down, of course, but it also has a "sunroof" setting. In that position, just the front seats are uncovered. It's especially handy if you're just making a quick trip and want that open-top feeling without waiting for the roof to completely lower then raise again.
The Mini's one major problem is rear visibility. That's often an issue in cloth-top convertibles when the top is raised, but in this car the folded top blocks your rear view when it's down.