Advance Auto Parts offers the Gumout Multi-System Tune-Up 16-oz. Bottle for $8.99. An $8.99 online rebate cuts the price to $0. Opt for in-store pickup to dodge the $9.99 shipping charge. That's tied with our mention from last week, $9 off, and the lowest total price we've seen for this fuel system additive. Deal ends July 30.