Amazon offers the Armor All Ultra Shine Wash & Wax 64-oz. Bottle, model no. 10346, for $3.89. Order via Subscribe & Save to drop it to $3.31 and bag free shipping. That's tied with our June mention as the lowest total price we've seen. (It's also about a buck less than you could expect to pay in local stores.)
Note: Be sure to cancel Subscribe & Save once your order ships; otherwise, you'll be billed for subsequent shipments.