That's possible, but lack of insight into what's easy or hard in manufacturing or construction is a pretty common problem. I saw it a number of times when working for a few different manufacturing companies, though none of them built cars.
A failure to understand construction concerns also played a role in the Hyatt Regency walkway collapse. The original design was poor, but redesign to address construction difficulties accidentally weakened the walkways further.
> Havens Steel Company, the contractor responsible for manufacturing the rods, objected to the original plan, since it required the whole of the rod below the fourth floor to be screw threaded in order to screw on the nuts to hold the fourth floor walkway in place. These threads would probably have been damaged and rendered unusable as the structure for the fourth floor was hoisted into position with the rods in place. Havens therefore proposed an alternate plan in which two separate sets of tie rods would be used: one connecting the fourth floor walkway to the ceiling, and the other connecting the second floor walkway to the fourth floor walkway.
> This design change proved fatal. In the original design, the beams of the fourth floor walkway had to support only the weight of the fourth floor walkway, with the weight of the second floor walkway supported completely by the rods. In the revised design, however, the fourth floor beams were required to support both the fourth floor walkway and the second floor walkway hanging from it.
There was another problem -- the beams were spec'd as box section, but what was on the shop drawings was 2 channel sections with the flanges welded together. (like this: []). The attachment point that supported twice the design load was also compromised by the weld and less competent section. Whoever was checking the shop drawings didn't pick up on the importance of the change.
IIRC, either change on it's own would have been marginally ok, the two together weren't. (by marginally, I mean probably wouldn't have killed people but wouldn't be to code)
When I was going through civil engineering, there was a big push to use a statistical basis for loads and resistances, rather than using a blanket factor of safety. Loads vary, strengths vary, potentially normally, probably not. But they're described by statistics at any rate. Blunders of this sort aren't, at least on a per project basis.
A failure to understand construction concerns also played a role in the Hyatt Regency walkway collapse. The original design was poor, but redesign to address construction difficulties accidentally weakened the walkways further.
> Havens Steel Company, the contractor responsible for manufacturing the rods, objected to the original plan, since it required the whole of the rod below the fourth floor to be screw threaded in order to screw on the nuts to hold the fourth floor walkway in place. These threads would probably have been damaged and rendered unusable as the structure for the fourth floor was hoisted into position with the rods in place. Havens therefore proposed an alternate plan in which two separate sets of tie rods would be used: one connecting the fourth floor walkway to the ceiling, and the other connecting the second floor walkway to the fourth floor walkway.
> This design change proved fatal. In the original design, the beams of the fourth floor walkway had to support only the weight of the fourth floor walkway, with the weight of the second floor walkway supported completely by the rods. In the revised design, however, the fourth floor beams were required to support both the fourth floor walkway and the second floor walkway hanging from it.
https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse...