Some of these problems have been continuous since 2013. While you can call them "growing pains", at some point they become part of corporate culture -- after all, Tesla will continue to grow. I predict they won't improve much unless actual action is taken.
Since the beginning spare parts have been a problem as well as service center access. When Teslas were most common in islands around a relative handful of cities and the fleet was small, they could get away with a small number of service centers, but now getting to a service center is difficult for more people, getting an appointment can be difficult, and while ranger service can cover some things, others require a trip to the service center. For me it's 4 hours out of the week to take my car in, for others in Oregon, it is either one very long day or an overnight trip because there is one service center between Sacramento and Seattle and the coast and Salt Lake City.
From what I've heard, the body shops connected to service centers are quicker turn around than private body shops, but Tesla should stock enough spare parts and put enough priority on sending out parts that it isn't a big problem to get parts for private body shops. And there are not enough Tesla body shops to go around. The nearest one to here is Bellevue, about 3 1/2 hours drive. There was someone in the local Portland Tesla group who did take his damaged Model S to Bellevue and had a good experience, but it was a 2 day trip.
I used to have a Buick Roadmaster, which had a total production over 5 years less than the Model S at this point. I backed into a tree that was leaning over a fence when the car was 5 months old and had to get the trunk lid replaced (the tree hit the trunk lid right on the bend). A local body shop got a trunk lid out of GM in a couple of days. There were maybe 50,000 of these cars on the road at that time, but GM had the parts ready to go.
Making the car so safe it never gets into an accident is a good goal, but it isn't realistic. Even if the car has the best collision avoidance system in the world (which Teslas don't have), the car can still get hit when parked and all systems are turned off. Tesla has been so focused on getting cars out the door, they neglect spare parts for damaged cars. The company owned body shops are not the best answer. They will never get the coverage of private body shops.
Tesla is also a walled garden about service. They are softening up, but they still aren't there. They need to have third party, certified mechanics able to work on these cars. There are a number of Teslas in Bend, OR now, but the nearest service center is in Portland, a mountain range and over 3 hours. This time of year the road can be closed due to snow and the lower altitude route could be a 5 hour drive. Ranger service is available, but they can't touch the car if it needs to be put on a lift. A local auto shop could service these cars if Tesla would let them.
Tesla seems to think that because electric cars need less maintenance, they need less service center support. That may be true over the long haul, but that doesn't help with initial quality problems or problems in systems other than the drive systems.
It's been 6 years and Tesla's response to these problems thus far has been poor.
