We had a basic mirror which suctioned to the rear window in front of the infant seat, so we could see her in our rear view mirror. But I never felt like it was super safe and would become a projectile in an accident. It actually fell off the window recently, which proves to me that it was unsafe anyway.

So, recommend the specific mirror you have and like please! We don't have a head rest in the middle seat where the car seat is, unfortunately.