You could be right. My understanding has been that the overseas Chevettes were rebadged (Vauxhall, Isuzu, Holden, etc.) Opel Kadetts. They certainly all had Kadett bodies.
At the very least, the Chevettes in the Americas had a unique body; it did not look at all like a Kadett. It would make sense that GM would design such a small car as a "world car" and tailor the styling of the domestic version to suit American tastes.
(On a related note, I recall U.S. Buick dealers sold Opel Kadetts for a few years in the '70s.)
Thanks. I learned something today (even if it proves to be entirely useless trivia ;O).
I had to look it up online.