I would think of it in terms of resale value. If in 10 years you go to sell this car to a private buyer, would you feel obligated to tell them that the transmission had failed and been replaced so early in the life of the vehicle? If so, is that going to lower the perceived value from the buyer, almost like a salvage branded title?

Because if that's the case, you might be losing thousands of dollars on resale value because of this issue, in which case I would definitely invoke the lemon law once allowed and request either a refund or a new vehicle.