by accounting rules they are in inventory even if in transit to the end customers. (actually for exports they can count delivery at the port).
so the concern is still there that they have increased "unsold" vehicles.
The 10Q will have more detail to help work out if there is a glut of models sitting idle in a particular country or if they need this number in transit at all times.
They are every quarter because production continues to outpace sales which is partly why Tesla has to continue to cut prices to keep sales up with production.
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