Coupon code is what you would expect. In the online store, these are code provides additional discounts and offers with your purchase. These can reduce the total cost or at a constant rate, thereby saving any particular or specific items such as the transmission. When combined with regular offers and savings, they can give the desired items at a very low price. At a lower cost, than you want, you can save a little more money after each purchase, or simply afford to get the higher quality items.