Own arises when the assemblers do not deliver car timely to buyers. If everyone knows that the car they booked will be delivered within 15 days to a month, just like anywhere else in the world, there wouldn't be any own.
So theoretically at least, delivery would be delayed only when the demand is consistently higher than the maximum production capacity of the factory. This is certainly not the case right now as capacity utilization of big 3 is around 40-50%. So there wouldn't be any own or delayed delivery even if the demand is double the current level.
But yeah, the car companies know that there would still be some buyers/investors who can afford these prices. Also, a pressure tactic to Govt to either reduce import duties on CKD units / tax relaxations or else factory closure that would render thousands of employees jobless that could blow up into a social issue.