New images of the BMW M4 Concept have hit the Web, ahead of the vehicle's debut this weekend at Pebble Beach. We don't know the full specs yet, though it's expected power will come from a turbocharged inline six producing something in the range of 450 horsepower. A new cosmetic feature takes the form of a tri-color stripe that runs the length of the carbon fiber roof on the driver’s side, while the 20-inch M alloy wheels sport a five-spoke design. Additional characteristic M features include redesigned gills on the car's side panels, as well as twin carbon fibre tailpipes underneath sculptural rear apron. A carbon fibre rear diffuser completes the overall aerodynamics package. Check out more looks in the gallery below.