Production Manager Matt Elliott’s been creating these for over two years, so I asked him.
First, he told me that only two percent of the cars from each production run are Green Machine versions.  GreenLight includes them in every scale it produces: 1:64, 1:24, and 1:18.  To put that in perspective, if GreenLight runs 5,000 pieces of a blue 1:64-scale 1964 Plymouth Fury, 100 of those will be Green Machines.
Look for the following traits.  Note that GreenLight-Green™ is a brilliant emerald-green metallic paint.
          1) GreenLight-Green Body
          2) GreenLight-Green Chassis
          3) GreenLight-Green Rims
          4) GreenLight-Green Interior
          5) Green Tires
A Green Machine can have one of these features, and occasionally a combination.  We hope the variety makes them harder for non-collectors to spot, and easier for them to get into your hands!

http://www.greenlightcollectibles.com/asse...een_machine.jpg