Whether the credit card handling fee of this store is reasonable or not depends on whether the user buys a car in full or with a loan.

If the user buys a car in full, it is unreasonable for the 4S shop to charge the credit card fee, because the fee is charged by the bank to the merchant and has nothing to do with the user. Merchants can't pass this fee on to consumers, otherwise it will infringe on the rights and interests of consumers.

If the user borrows money to buy a car, the 4S shop charges a reasonable fee for swiping the card, because the 4S shop needs to charge a certain fee for borrowing money to buy a car, which is an industry rule.