donnatella : I've always used the little plastic cups near the bbq sauce pumps.
@CaffeineFree : I don't like those tiny little cups. It is a real pain to stand and fill about 10 of them while ordering a togo order of any size. It might be fine for a single sandwich or if eating inside but to go orders should be prepared with a quantity of sauce that matches the amount of Q ordered. Unless a person specifically knew the routine they would just assume the sauce would be included like it every place else.