I’ve got to think that the ratio skews heavily to the side of custom for any of the Tesla. This is where Tesla’s intense vertical integration starts to be a detriment. I was just reading an article about how the vertical integration of Tesla was amazing in that it made it possible for custom components to be used that saved space and weight by performing more than one job . This is great - until you need to replace that one specialized part and you can’t seem to find it.
I laughed when I was looking at the cup holder for my new car. It’s a 2018 Audi A3. The rear cup holder is the same junky design that I had to replace multiple times in an old 2000 Jetta. It’s not a great design, even-though it saves space. However, because of all of the available suppliers for that part, I know I’ll be able to find a replacement of this for years. This type of parts availability is a blessing (you can find one cheap) and a curse (you are limited in how you can design the car by the parts that are already available, thus you can only have a barely functional cup holder).
...or when that multifunction part fails and renders much of the car inoperable.
Odd that that article about the Superbottle mentions "increased modularity" as an advantage, when it clearly decreases modularity to integrate so many functions into one monolithic part.