ok, heads up...
I had to call in that coupon code 800/875-8480. Customer service was open on sunday and very courteous and helpful. I have been ordering from OTC for the past 10 years and have never had a problem with them.
During the ordering process, there is a box asking for a key code from the catalog you are ordering from, this is where you put in the key code. It is beside the gift certificate box.