If I understand what you're referring to, a video display that shows a camera's rear view, rather than an actual mirror, there's a way to fix this using the smart mirror app while in-game or during a session (select from the right pop-out menu on the right). You can change the center mirror to a capital "M." A lower-case "m" makes it appear as an actual mirror, so it will reflect the interior of the car (depending on your smart mirror settings). Whoever creates a car with a video-display for the rear view, should set this so it's "M" at default.