iPad Car Headrest Mount or Stand - works with 9.7 in screen tablets.
Obviously, you have to print x2 of that for each rod on the headrest. 😃
I use it on old iPad 6th Generation, which is 9.7"
Prints with minor support. It needs one for the hook.
Probably a good idea to print it out of PETG. The one I've printed is with PLA and might be a bit fragile specialy in a car that has been out on 40 degree Celcius.