Right to repair laws would help things so much. If you didn’t like the firmware that came with the car, you could install alternative firmware. If the dealer sold a car that was known to have some terrible components, there would be a business opportunity for a car modder who would buy factory vehicles from the dealer and replace the most trouble-prone parts, then re-sell the car with a slight mark-up.

It used to be that when it came to high performance cars, there were groups like Alpine, AMG, Abarth, Shelby, Saleen, etc. They were often race teams, or associated with race teams. Sometimes they would buy stock cars and modify them for racing, or at least modify them for high performance. But, most of those have now been brought into the company most associated with them. Mercedes owns AMG, Alpine is part of Renault, etc. I would bet one reason that this is not as common anymore is that cars are heavily computerized, and the computers can use DRM to restrict anybody but the original manufacturer from modifying them.