I should be happy that I could use something that they want me to use? Really? I can understand them refusing to honor stacking, but I've never had them honor coupons in general. I've even had a store honor a coupon value after I had to return an online order that was defective.
With coupon codes, I've done almost all of my automotive purchases from AAP. I'll use the $10 off $30, $20 of $50, etc. codes all the time. I'll be placing another order in a few days for my new truck, but I have to come up with $75 worth of stuff after coupon since I have to get some items shipped. They aren't kept in stock at the stores and the online inventory always says "call store."