@carnage4life I remember before I bought my model 3 (in 2018) wondering about this same issue. I scoured the net and found posts by people who'd analyzed communications between the car and the mothership and were convincing that it was all not too complicated and both mapping and car network functions could likely be hacked into place with some python scripts on a rented server. Seemed reasonable enough.
There are enough of the cars out there that there'll be 3rd party repairs and parts.