I looked into licensing at one point when it seemed like my career would be heading in a different direction. As I understand it, my state defines "engineering" as anything that could affect public safety, and says that all engineers have to be licensed, but there are only exams in certain subject areas.

I think the guiding principle of engineering regulation would lead one to believe that software controls for a car should be covered by licensing, but that this has not occurred in practice due to the regulations not keeping up with technological change.