Converting a standard 71 cuda driver mirror to a remote sport mirror for a friend. How is the remote adjustment housing retained on the door panel? I know a chrome bezel screws onto the remote housing through the panel but what secures the bezel to the panel? Is there a retainer that attaches to the backside of the door panel. Also what location to drill the panel for the remote? Or do the back side of the door panel have an indentation of where to drill the hole. Thanks