I'm not sure that we know how much it costs yet but I don't think it will be $15k. It's unclear to me whether this exhaust is the same as the upcoming MPE, which will be Akrapovic. If so, that's your 15hp right there. The active M Differential sounds interesting, anything that improves traction is OK by me. Overall I'm curious, but it's certainly nothing that is making me itch to trade in. I'll think about it again in a few years when that time comes. The M6 is just such an amazing car as it is, I feel lucky to have it in the garage at all.
As for your comment about the brakes, I don't know, at this point I would almost be willing to spend $9k and survive a little cold weather break squeal to get rid of all the brake dust.
