well yeah, walk up to a new car and look at the sticker. They say what percentage of the car's parts are form where.
Example, the Chevy Aveo is just a Daewoo. The big three own most of the car companies out there. They will use parts form whatever part of the company they want to use parts from. The ford contour's transmission came from jaguar I think. Like I siad earlier, ford put the protoge engine in the new focus. Ford owns mazda.
A couple of the current Fords and some of the ones to come are just imports from their european division. Same with GM. They are international companies now, that just happen to start in the US. But most of their cars are international.
However, GM does not own Toyota, that's just a deal they have in the US.
Actually, I have seen a turn where people are prefering Honda and Toyota over Chevy and Ford in the US. I know a couple of people that have switched because they had better reliability.
It;s funny when shopping fo rcars. Many people think 100k on a car is alot. Bah. Depends on the car I guess. Any Honda and Toyota can last over 200k. I had a corolla with 180k on it before I got in an accident. My parents had a camry for 280k before the strut mounts rusted out. A friend of mine had a first year civic that was going strong when he got rid of it a couple of years ago. I just bought a used '92 camry v6 xle. Has 130k on it. Not a problem

However I am spoiling myself with the xle model. Leather, power everything, moonroof, cruise, ahhhhhhh. It was a southern car too so no or very little rust. We'll see if it can last a winter up here and not get rust... I don't think I could have a car anymore that doesn't have cruise or a moonroof.
You'll find a few "US" cars like that. I see dodge reliants, buick centuries, ford rangers that are pretty dang old running around, but over all not too much. I still see early 80s corollas and civics all over the place. I will see maybe one chevy beretta driven by a high schooler in a month, where as when I was in high school they were all over the place.
Though part of it is how popular leasing has become too. Alot of people lease these days because of how expensive cars are. So you don't see older ones around too much because of that.