Joining the existing BMW 435i Coupe-based Alpina B4 Bi-Turbo that was unwrapped at the 2013 Tokyo Motor Show last October is the hardtop convertible version teased here ahead of its world premiere at the upcoming Geneva Auto Show.
The Alpina B4 Bi-Turbo Cabrio is upgraded with the same exact parts that make the coupe edition a more interesting proposal than BMW's original 435i, beginning with the uprated 3.0-liter twin-turbocharged six that delivers 404hp (410PS) and 600 Nm (442 lb-ft), up from 306PS (302hp) and 400Nm (295 lb-ft).
The added weight of the retractable roof makes the Cabrio slightly slower than its fixed-top sibling, with a 0-100km/h (62mph) sprint time of 4.5 seconds and a top speed of 301km/h (187mph), versus 4.2 seconds and 305 km/h (190 mph) for the Coupe.
Rounding out the improvements are Alpina's chassis and understated styling tweaks such as the 20-inch wheels wrapped in 245/30 tires on the front and 265/30 on the rear axle, pin stripes, front apron and custom interior leather and trim accents.
In Germany, you'll be able to jump in the Alpina B4 Bi-Turbo Cabrio this spring for a tax-inclusive price of €74,800 (equal to $102,800), or roughly €6,000 more than the coupe.