Acclaimed BMW tuner has wasted no time preparing a new model in the shape of a BMW 4 Series-based B4. Expected to be launched next year after a formal introduction at the 2014 Geneva Motor Show, the Alpina B4 Biturbo has been spied in prototype form sporting some giveaway aftermarket gear. The most blatant is the quad-exhaust tips, followed by the tuner's 20-inch multi-spoke alloys and blue-painted brake calipers.

Power comes from the same twin-turbo variant of BMW's 3.0-liter straight-six rated at 410 hp and 442 lb-ft of torque (up from 300 hp and 300 lb-ft in the 435i) used in the B3 Biturbo sedan, enabling it to sprint from 0-62 mph in 4.2 seconds and hit a 190 mph top speed. The camo is undoubtedly hiding revised bumpers and spoilers, while other expected performance mods include an adjustable suspension and modified ZF eight-speed automatic box. An AWD Alpina B4 should be rolled out sometime down the road too.