On another note, is there a purpose to having "the most powerful F10 M5 in the U.S." or just merely bragging rights? Private party or tuner shop?
Not to complicate things but just plain out raw power is one thing but having usable power that won't prematurely detonate the power train is entirely different. Power that can be used throughout the RPM range (without significant lag or power delivery abruptness) instead of only a top RPM sweet spot. No offense but I just find this kind of thread talk a bit ridiculous. I can totally understand it though as many consumers will be drawn or tricked simply by focusing on peak horsepower gains.
If you're just talking about raw numbers, I'm sure if someone was brave enough (or stupid depending on your outlook) they'd just increase the boost and add power adders to get BIG peak numbers.