Wow, fantastic. About 3 years ago I did a rough calculation that BMW could save about 300 lb in the F8X M3 by going to an all CF chassis. See debate/discussion
here. Seems like that calculation was very reasonable in comparison to the 286 lb saved here, although this weight difference is not only due to the chassis alone but it is the largest component of the savings. My rough calculation also assumed a nearly complete CF chassis, which clearly is not the case here either. These errors/approximations are both consistent with the <300 lb actual achievement.