That’s not what I said, I said those were the parts of the car that really need to be crafted to break for safety. Your interior, electronics, your transmission, engine, etc. Can be designed with repair in mind like older cars. Most new cars are a pain to repair and not because they need to be.

The body and the chassis are really the only parts that need to be built for the sake of breaking for safety. The other parts on the car do not need to be disposable, but for the most they are. The part placement and design are not engineered with repair in mind.

It might be an altitude issue, higher elevation can make cookies look like that. I found high altitude cookie recipes and they puff up nicely.