My brother in law has a 2011 Silverado with the "standard" power mirrors. He is wanting to upgrade to the "towing" mirrors. Does anybody know if the harness can support the tow mirrors with turn signals and heat, or at least turn signal. I have a trailblazer and on that platform(gmt360) all the mirrors are plug and play because the body harness is wired for all options. Just curious if the silverado is the same way.