Just stumbled upon something claiming that this was the song playing in the Durango at the time:
http://www.youtube.com/watch?v=TDh0FcJ1atA
Mostly just linking it as a curiosity. It's pretty much what you'd expect. Only real direct relevance it has to the case is that the song does in fact contain phrases which match Dunn's claim that he briefly had difficulty discerning if what he was hearing was part of the song, them singing along with it, or something directed at him (to be clear, he was very firm on the fact that the utterances which directly led to him opening fire were unquestionably directed at him, and that Jordan Davis was saying them to him face to face.)
I would seriously doubt it. I think Corey sees this as her second shot at Zimmerman by proxy. Doesn't want anything less than the maximum charge, maximum penalty.