I find this baffling, the normally aspirated BMW engine produces nothing special by way of heat, pressure or stress, the manifold designs are pretty standard and use no exotic materials, so how the hell are they having these problems on low mileage well maintained units? I do admire the way BMWs perform but this sort of unnecessary fragility reminds me of the issues with boggo basic things like rear springs breaking up, cracking alloys, roof motors, window regulators etc
You just don't get these issues with something like a Honda so why can't BMW get these basics right?