I wrote a lengthy email to GMC to voice my disapproval of their advertisment dollars being spent on Sinclair. Because my family and I have a long history of purchasing GM automobiles a boycott would have some effect on their bottom line. Anybody that wants to write to GM can access proper cite at
http://www.gm.com/gmcomjsp/contactus/email.html
I received a response from GMC. Nothing substantial, slightly more than a polite thank your for your concern.