Lets say in 10 years, 3D printing technology become so advanced, almost anything can be perfectly replicated. So I find some leaked car 3d file, I download it, I print the car. What current laws would I be violating? Civil or criminal? And what future laws can you anticipate?
Even if you could print a lot of different materials: A modern car is uncredibly complicated and I’d even take a good enigneer months to fabricate something that does not kill you or others on its first drive. So I guess it won’t happen. What I could imagine however is decentralized and more local manufacturing of cars. One company may licence their design, it gets assembled remotely at several places and an engineer has a look before you get it.
In OP’s situation where they’re downloading a car, I think it’s a safe assumption that the car has already been designed/engineered and OP is just printing it out and assembling it. This would be akin to a kit car, and modern kit cars certainly don’t require specialized engineering skills to assemble.