Take a car. Have the germans decide how it should handle. Have the italians decide what it should look like, and what the interior should be like. Have the americans design the engine. Have the Japanese bolt everything together.
What do we have? A beautiful car with an amazing interior, awesome handling on the street and the track with a torquey engine that makes all the horsepowers with no sacrifice in MPG. An italian exotic that will never self immolate. An american engine with japanese build quality. European handling without the european repair bills.
It will never happen of course, but if it did, I think only such a beast could be worthy of the title 'global supercar'.