(1) Mini doesn't cut the top off its standard cars to create the convertible, it starts with stampings specific to the topless model, thus saving the time, effort, and money of altering an existing body-in-white. A tubular steel reinforcement is added to the A-pillar, a lower brace adds rigidity to the rear struts, and the floor and sills are strengthened via lower B-pillar cross bars and pan stiffeners to meet side impact requirements. Otherwise, the chassis is standard Mini, which was designed from the start to include a convertible model. Aluminum hoops behind the rear seat provide roll-over protection and act as upper mounts for the three-point rear seatbelts. The lack of a hardtop does reduce the number of airbags offered by two, however, leaving front and seat-mounted airbags, but eliminating the side-impact head bag found on the three-door.
(2) Engines are the same as the hardtop's, though the supercharged "S" model gains five horsepower (to 168 hp), while the non-boosted 1.6-liter four-cylinder soldiers on with 115 hp. Where the base engine gains, however, is in the replacement of the previous MG Rover-sourced five-speed gearbox with a Getrag transmission with the same number of speeds. Not only is the shift action on the new gearbox lighter and more precise, the gear ratios are more closely spaced for better off-the-line and in-gear performance. The six-speed Getrag used on the Mini Cooper S convertible also has closer ratios.
(3) Oasys Systems, a joint venture between Webasto and Pininfarina, designed and developed the convertible top. It has a heated glass window, multiple fabric layers, and does away with the need for a cover when lowered. A power sunroof is integrated into the top, and the first section of canvas–about 16-in.–slides back along the top rails when the top button is pressed the first time. It can be opened or closed while driving at speeds up to 75 mph. Holding the top button causes the roof to fold completely, with a "Z-mechanism" in the rear quarters folding it such that it stows neatly behind the seats while leaving 4.2 ft3 trunk space. (There's 5.8 ft3 with the top up.) The sunroof section rests on top, protecting the rest of the top from dirt, dust, and debris. The sunroof and top can be opened via the keyless remote, or closed by inserting the key into the door lock and holding it in the lock position. Unlike most small convertibles–and a number of larger, pricier soft tops–the Mini Convertible's top is fully automatic, and does not require the opening or closing of latches along the header. To preserve trunk space, the rear of the top can be unlocked and raised to 35º to increase the size of the rear opening. The outer-hinged trunk lid drops down for loading and can hold 175 lb.
(4) The front and rear fascias are subtly modified, and the light housings updated across the Mini line. Headlights receive a new reflector and bezel design, and a new reflector design increases the amount of light that reaches the road. The optional Xenon headlamps receive new teardrop-shaped light ports around the edge of the Xenon element. This not only delineates the more-expensive lighting unit from its more prosaic brother, it brings a new interpretation of the "Angel Eyes" lighting units found on BMW-badged vehicles. The taillights also are new, and include integral reverse lights, which eliminate the central light previously found on the lower rear bumper fascia. Because of the wide sail panels, all Mini Convertibles come standard with parking sensors mounted in the rear fascia.