From a BMW forum:
The thing no reviewer can mention is, lets see how the Camaro feels in 5 years with 60,000 miles on it.
I had a 335 that was 6 years old with 50,000 miles on it and it felt and sounded exactly the same as it did when I bought it with 7000 miles on it 3 years prior.
That's the thing with the Americans, because they build them at a way cheaper price point, something has got to give and that is by the quality of the assembly of parts. So after a few years and 10s of thousands of miles, they loosen up, rattle, squeek, etc.
This reminds me of delusional VW/Audi people.
Of course, I'm not saying that at one point, there wasn't a lot of truth to the statement. But also that it hasn't been true for quite some time.