So I've been on a mission to track down installs of this mirror (84350225) before pulling the trigger. A number of folks on the Volt forum (mirror is compatible with a number of chevy vehicles), folks have been disappointed that the garage door opener is detachable and battery operated. The big plus is that the mirror is frameless. That to me isn't enough to spend the extra $60-90 and pull the trigger, so I'm going the route of buying and installing 13581082 and just use my old school garage remote clipped onto my visor.
Thanks to all who helped pull this tutorial together.