Cars are mass produced, mostly by robots, in very controlled environments.
Seventy five percent of the car is made up of parts from 3rd party suppliers.
It makes no difference where the car is assembled - south African produced e46's were not less well built or less reliable than German built models.
It's 2011, there's no such thing as a true German, or American or British car any longer (unless you go boutique, and even then....).
2000 Mercedes Benz E320 (daily driver)
2007 Infiniti M35x (wife's)
2006 330 cic ZHP 6sp (current)
2005 Z4 3.0 sp nav x-leather (retired)
2000 323i PP (best car, ever - retired)