I'm just wondering if a kid watches a full movie through streaming, will that rack up the cellular bill? I remember around 2006, there was a flip phone that was able to watch TV shows live, and thought that was so cool. And now it seemed that idea just turned into streaming rather than watching TV shows traditionally.
Most the time, places like trains / airplanes / hotels usually have WiFi if an adult isn't driving.
I find it hard to enjoy movies while in a car, I rather just look outside even if I was passenger.
Have you looked at a mount from ProClip? They sell all kinds of mounts, including for iPads. These would require you to get a little creative with mounting them. If you’re looking for something permanent, you could mount directly onto the seat back. The screws they use are fairly small, so they wouldn’t leave humongous holes in the seat back. But that’s something you’d have to grapple with. It’s possible 2-sided 3M tape would work.