Maybe cars are complicated and it takes more than six years to figure out how to make them well? Maybe Tesla is using a very different process to make the Mode

Maybe cars are complicated and it takes more than six years to figure out how to make them well? Maybe Tesla is using a very different process to make the Model 3 than the model S? Maybe we shouldn't compare a car that's been in production (with some changes) for 17 years with a car that's been in production for a couple months? The Model 3 is substantially different than the Model S and has been in production a couple months. Just because Tesla made a similar car before doesn't mean that making cars is a solved problem and there won't be new problems with each new model that have to be overcome.