> Building "a" car isn't that hard.
Tesla deserves plenty of accolades just for getting to the point where they are producing multiple models of vehicle that conform to or exceed modern standards of quality .
However, Tthey have only managed to build "a" luxury sedan, "a" crossover SUV, and will soon be building "a" budget-luxury sedan. The real challenge is in attaining and sustaining the pace of development maintained by the rest of the industry. The automotive industry at large keeps a rolling cycle of refreshes and replacements on a roughly 3/6 year timetable (refreshed after 3 years, replaced after 6). Some niche models (Jeep Wrangler, Mazda Miata) stay in production far longer than that average but a 3/6 cycle is also a bit too long in ultra-competitive categories such as the compact crossover segment.
This is where I see Tesla beginning to struggle as their entirely bootstrapped operation has struggled to meet deadlines. That is cause for concern as it places their current lineup at a competitive disadvantage as their competition has gone through at least 1 refresh, if not a full replacement, since the design of their most recent model (Model X) was set in stone.
The Model S design was largely set in stone by 2009, 2010 at the latest and the Model X design was mostly locked in by 2012, 2013 at the latest. It took 3 years for both of those designs to actually reach showroom floors (2012 and 2016 respectively) so while the clock hasn't run out in terms of production life, the designs themselves are beginning to become dates. I don't just mean "design" as in styling, I mean it as the all-encompassing architecture of the vehicles.
While Tesla's offerings have several unique attributes which cannot be found in any of their closest competitors, one can only push an old design for so long before it becomes completely unappealing to consumers, even when sold at break even prices. I dare say that such a scenario may be playing out with the Model S as its sales had slumped leading up to the 2016 refresh that boosted sales, yet the bump still fell short of that model's best sales quarter which occurred back in 2015. The fact is that the Model S was designed to achieve the minimum level of refinement expected of a 2010-era, $65,000 luxury sedan with the silent, powerful electric powertrain being the plan to make up for its shortcomings in the areas of ride quality and interior fit and finish. Now that ~7 years have passed, the high end, mid-size sedan offerings from mass market brands have caught up to the Model S in many areas.
The Model S may smoke a Nissan Maxima in straight line and the Maxima can't hold a candle to the silence of the Tesla's powertrain but it also costs ~$35,000. In my opinion, it also has a better finished interior and more up-to-date styling than the Model S. We can argue all day over these points but you have to admit that manufacturers like Nissan are at least getting within striking distance in certain areas with cars costing half the price. Tesla needs to seriously step up their development game lest they be left behind with woefully dates products that simply cannot be discounted enough to remain appealing.