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.
A new car lasts for about 6 years, needs upkeep like an old car, and has little if any resale value. You then buy a new car, using more materials many that are plastic and cannot be recycled. Even a electric car is not green, the batteries alone are a mess, not really recyclable and made of non-renewable resources. New cars are not meant to be re-used and repaired they are disposable like everything else in our society. What we should have as an environmental goal should be a dynamic public transportation, right to repair, and end our disposable ways.
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.