Watch the Hubcap Annie online guitar lesson by Robbie Calvo from The Rhythm Architect
In the words of Randy Jackson, "so, check it out dog!" Double-stops are just wonderful guitar parts to superimpose over other chords because they take up very little harmonic real estate but imply the chords and outline them none the less.
This guitar part really does outline the harmony very well and even adds its own flavor to the vibe. Try coming up with your own double-stop line over this progression, send your compositions to Simon Cowell Fox TV!