http://www.musclecaroftheweek.com - We've featured some pretty rare cars on Muscle Car Of The Week, and this one tops the list! This 1969 Plymouth Road Runner convertible would be cool with any power plant, but the fact that the Air Grabber hood is hiding an original 425 HP 426 HEMI V8 coupled to a 4-speed transmission makes this one of the rarest 'Runners out there! Reports claim 10 of these cars were equipped with the 426 HEMI in drop-top form, and only a couple are said to exist today. This F8 Green monster was featured at the 2013 Muscle Car and Corvette Nationals in the Road Runner Invitational display and is one of the prized Plymouths in The Brothers Collection.