As much as I am pro-FOSS, don't vehicle manufacturers have a right to copyright protection too? Why should vehicle computers be somehow different from other com

As much as I am pro-FOSS, don't vehicle manufacturers have a right to copyright protection too? Why should vehicle computers be somehow different from other computers, which we allow to run proprietary code? I guess my point is that, even being a FOSS advocate and pro-DIY, I don't see why car makers should be compelled to hand over their code, unless of course they're already using GPLed or similar OSS code. Troubleshooting diagrams would be reasonable to ask for, or perhaps some documentation of the protocols used. But demanding that a company release their source code because you essentially feel entitled to it is pushing the buck if you ask me.