There was a time in America's auto and truck manufacturing history when the raw materials
would show up at one end of the factory and a finished product would roll out the other end.
Not exactly, at least since WWII. For example, GM owned many different factories to manufacture parts that were ultimately shipped to an assembly plants. Delco-Remey did electrical components, while others' produced transmissions, frames, and Fisher body, for example, made the bodies. Also, there were other sources like Borg-Warner that produced transmissions for GM, Chrysler, etc.
The difference now is that most of those OEM component factories have been sold off or GM and the others use some other source.
What Peter is trying to do is buy parts from other component manufacturer's and build a car that he can claim as his own.
Don't know if it matters, but, imo, high dollar cars that Peter is trying to complete with, have their name on every part. Certainly Porsche doesn't use a Honda engine.
"The end does not justify the means" jmho