I got an email from Advance Auto Parts... Most everything is 20%. You have to order it online, but can pick it up from a store. (Apparently you CAN'T just walk into the store and get 20%.)
Use the promo code LABOR when you check out.
I'm going to do some maint. this weekend and I got two 1qt bottles of Mobil1 75w-90 gear lube for $17.58 + tax.
Also, if you spend $100 or more, they'll send you a $50 off $100 coupon for a future purchase. I don't know if I need enough stuff to get that, but I thought I'd put it out there.