Folks, not everything recommended by manufacturers are best for your car, like 15K-mile oil changes and 5/20 oil (not the case with the M3), to name a few. And no, there're no 'abrasives' in factory oil
There're many reasons behind the break-in interval, and I suspect the main one is to avoid many Andretti wannabes wading themselves on a tree before getting used to their new cars. And on the mechanical side, there're many other components besides the engine that need break-in, like brakes, tranny, and differential. More than engine damage, I'd worry more about developing a whiny differential if driving the car at sustained high speeds too early. But yes, you can drive the car flat out right off the bat, like most demos experience, without apparent consequences... other than shortening the life of mechanical components. By how much? That's anybody's guess. And my other guess is original owners will never find out; that's why it's so important to buy a used car (NOT LEASED) from as few owners as possible (from original owner is best), and with as few miles as possible. Good day gang.