BMW planned to reveal is Concept M4 on Friday, but images like this one forced the maker's hand.

BMW is reluctantly confirming it will reveal the new Concept M4 in Pebble Beach this week, part of the frenzied run-up to the annual Concours d’Elegance many makers are using to introduce their latest luxury models.

The German maker had hopes to keep things secret until a dramatic unveiling on Friday at the Quail Motorsports Gathering, an event that precedes the yearly Pebble Beach Concours, but images and details have begun leaking out on the Internet.

“The BMW Concept M4 Coupe reflects the BMW M philosophy in ideal form: It combines motor racing genes and unrestricted everyday suitability in a highly emotional overall concept,” said Friedrich Nitschke, chairman of BMW’s managing board, in a statement.

BMW has rapidly expanded both its mainstream and performance line-ups, but the maker has had a tradition of waiting before adding an M-badged model after updating one of its regular products. That approach apparently is shifting with the debut of the all-new 4-Series just this past June. If the Concept M4 is any indication, the production performance model could reach showrooms soon after less sporty versions of the new coupe line.

The BMW Concept M4 had its debut spoiled by an Internet leak.

Based on images first posted online by Auto55, the BMW M4 Coupe Concept gets a grille similar to the bigger M6 Coupe, with LED accented headlamps, distinctive aero mirrors, a “power dome” on the hood and a carbon fiber roof and CF front lip spoiler. There will be additional weight-saving measures that could trim the mass of the M model by as much as 200 pounds.

(BMW reveals new i8 plug-in hybrid prototype. Click Here for more information.)

Previous reports have suggested the new M4 would go with a twin-turbo 3.0-liter iinline-six making as much as 450 horsepower and 405 pound-feet of torque. That is likely to deliver a 0 to 60 launch in just over 4.0 seconds.

Until now, BMW had only confirmed it would show “a never before seen concept from BMW M” at the Quail gathering.

(Click Here for more about the new i3 introduction.)

The M4 Coupe Concept will return for a more formal unveiling at the Frankfurt Motor Show next month.