On Thursday, we told you that BMW is rumored to be readying a lightly veiled concept version of the next M3 sedan for the 2013 Geneva Motor Show.

But since that’s a long time to wait, the crew from Bimmerpost secured a spy video of one of the newest prototype models of the M3 performance sedan while undergoing hot weather testing in Spain.

The footage not only shows the exterior of the car but also teases the engine sounds, which are believed to come from a newly developed inline-six boosted by two, or as some sources suggest, three turbochargers for an output that should be greater than the 414-horses (420PS) delivered by the current generation’s 4.0-liter naturally aspirated V8.

Check out the video that follows below and let us know what you think in the comments area.

VIDEO