Just as the BMW 3-Series Coupe and Convertible were updated for the 2011 model year, so is the high-performance M3 variant, which has been captured here testing in prototype form.

The only noticeable difference between the current model and this latest prototype is the slightly revised tail lamps, which get new LED elements. Most of the visual changes are expected to take place inside and will include improved trim, a new center armrest and a second-generation iDrive system with four selector buttons for commonly used features such as the stereo. The iDrive system should also feature a new 8.8 inch LCD display and an optional 80 GB hard drive music and navigation system.

Power levels will remain unchanged, meaning the high-revving 4.0-liter V-8 from the current model will carry over with a peak output of 420 horsepower. One possibility is the addition of fuel-saving engine stop-start system, though BMW is yet to make any announcements of such a move for its M cars.

Expect the facelifted 2011 BMW M3, in both Coupe and Convertible variants, to debut at next month’s 2010 Geneva Motor Show.