Taking the “four” in the back Convertible (F33), Alpina specialists done with it all the same thing as a coupe. In addition, Alpina B4 Bi-Turbo Cabrio sport a new front bumper, a small spoiler on the trunk lid and the four round tailpipes of the exhaust system. And under the hood, tuning convertible located 410-hp three-liter V6 petrol engine with Twin Turbo, which develops a peak torque of 600 Nm. From zero to hundreds of model accelerates in 4.5 seconds (0.3 sec. Longer than the lighter coupe), and a top speed of 301 km/h against 305 at the car without the retractable roof. Price Alpina B4 Bi-Turbo Cabrio starts at 74,800 euros.