Honda cars have GM parts in them...like the Alternators and batteries.
You have your information backward. Small components like alternator and batteries come from third party suppliers that sell to the entire industry. On the the other hand some GM cars leave the factory with Honda V6 engines.
That's what I was trying to get at in my prior post. So no matter what the money involved, If I was Honda, I would tell the competition (GM) to go stuff it. Conversely, If I was GM, I would tell the competition Honda to go and stuff it. But yet it seems they are collaborating together and also competing with each other at the same time for market share of car sales. I was referring to engine R & D as was mentioned in a previous post by Danronian.
I don't think I was clear in my post. I was up for 24 hours.