Up til now they've only been doing relatively low volume production. I doubt Bently could scale up either and they know a bit about making cars.
Also, Bentley is fully owned by Volkswagen. If they wanted to "scale up" to a downmarket Model 3 equivalent, they'd take the VW MQB platform, use most of the non-platform components from the Mk7 VW Jetta (probably offering the 250hp and 300hp engines with AWD), spend 2-3 years developing sufficiently distinct styling parts, and then be able to churn out 100k cars per year.
But how much of a Tesla is Tesla? Don't large parts come from suppliers, e.g. all the seats from Lear corp? Or did they re-engineer those too?
I think the Ford F150 truck is the benchmark, in the U.S. there are 3000-4000 made a week. The price starts around the price of the Model 3 and then goes up and up with options.
Plus you get a lot of truck for that compared to a car, and due to the Chicken Tax there are incentives to buy the things.
Recently there was a fire in a supplier plant that affected the F150, with JIT they had to close the lines. But then they shipped the dies to England and restarted making the vital parts so production is back on. Really Musk should not be making promises if even the mighty Ford F150 truck can be brought to a production halt due to one fire in one supplier factory.
That story is quite interesting and right now there is a 747 flying those parts back from England to make sure Ford can keep on getting their $40 billion in revenue from selling that truck.
https://eu.freep.com/story/money/cars/2018/05/16/ford-launch...
I would be intrigued to know the numbers of vehicles per employee for the F150. Note how there is zero export potential for the F150 for a multitude of reasons whereas the Tesla products are definitely hot in international markets.
One of the problems for Tesla is that they make a bunch of things in-house that other manufacturers don't (e.g. seats).
https://jalopnik.com/tesla-is-still-figuring-out-the-model-3...
https://www.forbes.com/sites/joannmuller/2018/02/16/tesla-th...
The people that work for Toyota and GM aren't stupid, and those organizations have been at this game since before Elon was born.
Ford is withdrawing from the sedan market.
All US manufacturers with their decades of experience were almost destroyed by Asian manufacturers in terms of cost and build quality.
GM went bankrupt at least once in recent history.
The game has changed many times. It will keep changing, and in five years we will see that anyone not mass producing EVs as real products and not mere compliance vehicles is exiting the automotive industry.