Forbes , May 8, 2006 issue p. 58.
Canada U.S. content of a new Ford Mustang : 65%
Canada U.S. content of a new Toyota Sienna: 90%
The article is called Parts Paradox: and describes how the big U.S. parts suppliers are unable to make money on U.S. operations, but do very well with the overseas units. For example, Delphi wants to keep just 8 of its U.S. plants and...130 of its overseas plants. Visteon, Fords's Delphi, has 20 U.S. plants and 94 overseas.
On the other hand, foreign parts manufacturers are moving production INTO the U.S. (dodging tariffs, currency swings, and transportation costs, they usually locate in non-union regions, sometimes buy struggling U.S. plants cheap).
Interesting dynamic.