I have not checked it on the C7 but on other cars I have had the outside mirror dims when the inside one does. There is a light sensor on the inside mirror. I am sure that you could cover that sensor or disconnect one of the wires that control the mirror inside the door panel and it would turn off the auto dim feature. I have tinted windows on my Camaro and the dimming does not bother me. Just remember that this information could be worth just what you paid for it. NOTHING