Sorry guys, but CaptainKirk is correct. There is no reason to change the Tesla Motors signature door handles for the Model ☰. It is the internal mechanism, which allows the door handles to slide out, which allows for the latching, which has already been designed, developed, deployed, and demonstrated as being practical, useful, and really quite cool.
I'm pretty sure this is done in-house, it would actually cost more at this point to have something that was obviously off-the-shelf from an outside vendor. It would cost more in design time, because you would have to redesign doors, latches, and linkages instead of using something you already know works. It would cost more in stocking inventory, because you would have to keep something else on hand at the factory to do installations, and something else on the shelves at every Service Center to do repairs. It would cost more in training, because you would have to teach factory personnel as well as Service Center Technicians, and Rangers to reach for a different set of parts and why, and how to tell them apart.
Besides, do you really want a Tesla Model ☰ to have door handles that are obviously lifted from the same parts bin as Hyundai or Kia? Of course not. It's bad enough that the steering wheel is so obviously from Mercedes-Daimler-Benz...
I don't understand this nickel-and-dime strategy that even Tesla Enthusiasts have adopted, and presume will be necessary, to supposedly 'save money' by cheaping out on the Tesla Model ☰. That's exactly what all the Naysayers expect, and in fact, hope to see come to fruition -- because they know it will result in failure. They look at cars like the Ford Focus Electric, and presume that is the best that can be managed at a ~$35,000 price point for a fully electric car. After all, if one of the big boys, Ford Motor Co, can only manage that with all their manufacturing prowess and the economies of scale that commands behind them, then surely that means Tesla Motors can do no better... Right? Uh... WRONG. If you really think that is the best that Ford can do, I suggest you take another look. They aren't even trying to make a decent, affordable, desirable, electric car for the money. They want to perpetuate the notion that you should spend that kind of money on a hybrid instead, and would much rather you bought a Ford Fusion Energi -- which offers even less electric range.
So the list of 'cheap stuff to save money' should be abandoned in favor of 'good stuff to make money' because the goal is to make desirable, compelling, affordable electric vehicles. Remember, Tesla Motors gains a lot of margin simply by not having 'independent franchised dealerships' between the product and the Customer, stripping away profitability and development funds. So no... there won't be hand crank windows, or steel wheels, or regular knobs and buttons, or regular door handles, or regular keys, or regular mirrors (if it can be helped), or a smaller screen in the Model ☰. In this case 'regular' equals bland, boring, ordinary... mediocre, and none of those are desirable or compelling.
Your margins with suppliers are much better at 350,000 units per year than they are at 35,000 per year. Getting it right the first time, instead of futzing around, will make it more likely you can eventually reach 3,500,000 units per year, while spending even less per unit. By making your goals clear, and not compromising to reach them, you will be taken seriously by suppliers, who will allow you to build at quantity and within the margin you choose. This is how economies of scale are meant to be used, to provide as much to your Customers as possible, at the best possible price point, rather than giving them as little as possible, for as much as you can get away with...