A lot of cars companies restrict who can buy parts and what parts. For example if you want to buy the rear quarter panel for a Rivian you must be an approved repair shop and they will only allow so many in a given area. This is not specific to rivian. Lots of car companies do this with newer models. I have a friend who runs a high end repair shop and another who does restoration and the one who does Mercedes restoration won’t work on cars newer than x because he can’t get parts