This.Also agree on the absurdity of paying thousands for in-car entertainment systems. You can get a mobile whatever you want for so much less. We just have a $39 Kindle Fire for each kid. (Only on very long trips, because we're old fashioned and mean and make them, like, talk and look out the window and stuff.)
Our kids have their own tablets too, but we limit their screen time... the smaller and closer the screen is, the more judicious we get.