My son keeps stealing my wife’s phone on long trips. So we needed a sturdy headrest mount that could withstand the punishment of our toddler’s temper tantrums. We purchased 1 at “5 and below” for a Nintendo Switch but it didn’t fit right. I used the base from that to hook it to the headrest. (https://www.fivebelow.com/products/car-headrest-mount-for-switch). The enclosure for the fire is held together with 1/4 heat inserts and 1/4 20 1/2 hex bolts. It can also be attached to anything with a 1/4 camera mount. I used a spare ball mount to attach it to the old headrest mount.
You can download the files here if you wish to make one yourself: https://www.thingiverse.com/thing:5967903