Flag Content?

I'm a writer at www.cargurus.com/blog and have followed MotorWeek for about 5 years. We've had a debate on our blog about what makes a "domestic" car. For example: is the Ford Fusion made in Mexico more American, or the Toyota Tundra built in the United States? I'd be interested in your take, as I believe the global marketplace will only continue to blur the lines between domestic and foreign. Thank you!