I can tell the difference quite easily. Americans buying european cars improves european economies. Americans buying chinese cars improves chinese economies. What I can't figure out is what would happen if Americans were to buy american cars. hmmm.
Ok, I'm Canadian but this theoretically holds true as well. The problem is that back in 2006 when I was looking to buy a car, the domestics weren't building anything I was interested in. I was looking for a reasonably sized sedan that had a diesel engine in it. Guess what, the only car on the market with that feature was the VW Jetta (Manufactured in Mexico from German parts). Had any of the domestics built something similar, I'd have considered it, but they were all on the huge "HEMI RWAWWWR POWAH" bandwagon.
When my Jetta eventually wears out (8 years old now, and still going strong), I'll probably replace the sedan with a wagon. Guess what, none of the domestics produce a real station wagon any more... You either have to go with those stupid crossovers or something larger. Now, if the domestics would import some of their european models into the North American market, I'd strongly consider them. Over the years, I've had a wide variety of european Fords and other vehicles that I would love to buy, but they just won't sell them to us.