I used a Ram iPad mount and suctioned it to the pano roof for a trip between Connecticut and Florida with my 14yo daughter and her friend. They watched movies with sound through the car sound system. It was positioned on one side so it didn't block my rear view. Worked great.
Benefit is that they were looking up not down so no issues with motion sickness.
Not sure about the crash concern. it would be a projectile regardless of where it is during a crash.