The upcoming F80 BMW M3 was spied once again during the winter testing sessions.

The 2014 BMW M3 Sedan builds atop the newly unveiled F30 3 Series and will incorporate the usual M design cues, both on the inside and outside.

The prototypes spotted reveal a typical M3 with a wide track, M front bumper, square LED headlights, large brakes and the signature four exhaust pipes at the rear.

While BMW toyed with the idea of a V6 engine in the next M3, sources close to the company and our sister-magazine BimmerToday, say that the Garching-based division has settled on a six-cylinder turbocharged engine with a 3.3 liter displacement, a unique setup for the M car. The engine will produce around 450 horsepower and performance will most likely exceed the one of the current E90 M3.

To keep the weight down, the F80 M3 will make extensive use of carbon fiber.

Our sources continue to hint a two version of the very popular M car: an M3 based on the F30 3 Series Sedan and for the first time, M4 model built atop the new 4 Series Coupe.

The two videos below show the F80 M3 in Sweden, as well as in Germany on the autobahn chased by a BMW 1M with 420 horsepower.

(Photo: Pixner / BimmerParts-Online.com)