I was in the business 45 years. The responses are accurate as to the overall trend of whether your product is good or bad. The trend.

No manufacturer truly builds an auto any more. They merely assemble from parts bought from various suppliers for the most part. Now the big boys (Ford/GM will design and build engines and transmissions) but that is fairly rare. They even sell to all sorts of other brands. But generally speaking most of even their vehicles are a composite of supplier parts. For the new 2019's Ford is building the GM truck transmission and GM is building the Ford and Lincoln big SUV transmissions.

Suppliers have different grade materials and products they offer so the inexpensive brands can remain inexpensive. Among other considerations. For instance a few years ago Chrysler was on their arse. They made a top mgt decision to undercut Ford/GM pricing and also motivate their dealers. They started a stair step program paying the dealers huge volume incentives based upon monthly sales and aggressively advertised low prices and forced the dealers to honor those plus go even lower to make their bogie so the dealers got the business saving factory bogie cash at the end of the month. It was huge and the dealer's couldn't make a dime's worth of profit on the sales transactions so they were compelled to do what we called, LOL, whoring them out. And it worked like gangbusters for a time. The Fiat guy brought that to them and was the star of the industry for a time. C/Fiat paid for the price cutting and huge dealer bonuses by buying cheaper parts and lowering mfg costs. The Asians had been doing that for years. And predictably the JD Power numbers for Fiat Chrysler went into the tank.

The problem with Tesla is more complicated. (A) Money. They are broke and farming out parts and component purchases to.....China. (B) They don't really have experience in auto assembly and their plants are screwed up. As is their parts supplies and shipping. For instance they have customers in China so they would need a replacement part. The part would be shipped from China to Ca and then back to China. And (3) They have no dealer body structure in place. The few they had were factory owned or in co-op with an established dealer mall with another dealer selling maybe Fords and the Tesla was such a low volume thing that it becomes an after thought and even a distraction for that Ford dealer. I have seen them in Ca in malls either unattended or some locked. Owners waiting 5 months for a fender bender or 4 months for a mechanical repair is kinda normal plus the nearest dealer may be 150-250-500 miles away.