GM has been casting and assembling engines in Canada forever. Chrysler has been pre assembling in Mexico longer. Ford has "borrowed" entire chassis and drive trains, popped a nice body (The probe) revalved the shocks, and BINGO, American car!
The Ford "world car" gets 55 mpg. But it cannot be sold here, not "safe" enough. And so on, yet GM trots out the "Volt" as its' big incentive car. 40Miles max range? The Detroit Electric WW1 era got advertized 80 and up to 120 miles observed if things were "perfect". But only went 20 mph.