No parts of my own car in the mirror? (like spoiler or inside parts of the vehicle…)

Just wondering why are no parts of my own car visible in my Mirrors like in other games.
And why I never read about this topic anywhere?
I know, it reduces the visibility to the back, but adds a lot of immersion to feel like sitting in a real car.
Is it simply not possible within the engine, or why isn't it there?

Everyone who plays in VR and knows the modded 3d-Mirros in AC should understand what I mean. It looks just amazing and adds a lot to the feeling.