The hardware is, which is the important part at scale: even if the code is 10x more expensive when you sell millions of the car it becomes pennies/car

That’s a very old post but yeah, it is, so is Ghidra (a retro-engineering tool). A lot of people have had the exact same argument of “the NSA made it, it has to be evil!” but lots of security people dissected the code (the fact that it was made by the NSA probably made more people look through it in fact) and no backdoor has ever been found in years. It’s safe to use.