Lou Costabile’s camera catches a 1968 Mercury Cougar XR7-G at the Muscle Car and Corvette Nationals, a car most people would stroll right past. That single G on the badge ties it to racing legend Dan Gurney and a tiny production run built by A.O. Smith. Owner Brian Carpenter walks through the rare details and fires up its 390 big-block. Discover why Cougar collectors spend years hunting this exact model.