I believe you are right the Spark is built in China right now. But for the GM techs we use the 4th letter of the vin to let us know what kind of car we are working on and the 4th letter of the SPark is the same as the metro's. So there is some confusion there along with GM giving us service manuals on the car even thought we are US dealers.
To me the
N car is a Grand AM, Malibu
W car is the Century, Regal,Grand Prix
C car is the Park Ave
H car is the Lesabre
This is how we refer to cars and trucks among us techs most of the time. This is also how we find out how much each job on a certain car pays.