A virtually undisguised prototype of the BMW M4 Convertible was spied undergoing some last-minute testing, ahead of next month's very probable debut in New York.

A virtually undisguised prototype of the BMW M4 Convertible was spied undergoing some last-minute testing, ahead of next month's very probable debut in New York.

It's not that hard to imagine how the BMW M4 Convertible looks like once you check out a few official images of the recently introduced M3 Sedan and M4 Coupe. Equipped with a foldable hard top, the first ever M4 Convertible will be powered by the same engine as its two cousins, a 6-cylinder 3.0-liter TwinPower Turbo with 431 HP (317 kW) and 406 lb-ft (550 Nm).

The M4 Coupe needs 4.1 seconds until 62 mph (100 km/h) before hitting 174 mph (280 km/h) when equipped with the optional M Driver's Package but the M4 Cabriolet will be a bit slower due to a slightly increased curb weight. Gearbox choices will include the usual standard six-speed manual and the optional seven-speed M DCT. With the manual, the sprint is done in 4.3 seconds and if the M Driver's Package is not selected the top speed is electronically-capped at 155 mph (250 km/h).

The 2014 BMW M4 Convertible will likely be introduced in April at the New York Auto Show before going on sale in the second half of the year.

Gallery: BMW M4 Convertible drops most of its camouflage in latest spy pics