They've been in the business, probably are experts at cost reduction engineering. Their business is selling this information to other auto companies so they

They've been in the business, probably are experts at cost reduction engineering. Their business is selling this information to other auto companies so they must be right enough that they can get paid for it. There are potential reasons why the mentioned flange might be oversized, I'm having a hard time imagining how they tested frequency resonance and decided to just fix it by leaving a little extra material near where the welds go though. Or likewise deciding that the extra material in the weld zone increases safety by some margin. Those possibilities seem like they'd require and extremely nuanced and subtle understanding of the car and the whole process, It's possible, I guess. What's far more likely is that they just haven't done a round of cost reduction as they're just struggling to get the initial manufacturing done for the pre-orders.