You need to go back a lot further than just 10 years, its more like 20 years, and even then cars have been built on a global scale since the late 50s and early 60s.
If you want to get pedantic it goes all the way back the model T ford, which was built in almost all the countries it was sold in.
But it was during the 80s that manufactoring took a truely global meaning, and it started with Honda building assembly plants in the US (the first Japanese based manufactor to do so) and the buying up of smaller manufactors in Europe and Japan by GM and Ford.