However, if the car purchase price is lower than the minimum taxable value, 4S should inform the car owners before buying the car, because they know the minimum tax, which means that 4S has played a little trick or forgotten. I suggest you check with the tax bureau. If the situation is true, it must be returned, otherwise the vehicle registration cannot be handled.
This situation is relatively rare. Usually, cars with large discounts will appear, so you should consult clearly in advance.