I built this vehicle based media center from a Raspberry Pi 3, UPS PIco Plus HAT, and enclosed it in an old gutted DVD player.
The UPS PIco provides battery backup when the vehicle power is removed and sends a shutdown signal to gently halt Raspbian running KODI so the SD card doesn't get corrupted. When power is reapplied, the HAT triggers the Pi to restart.
Raspberry Pi 3 utilizes the built in WiFi for video transfers, updates, and phone tethering. Bluetooth isn't currently implemented, but could be used for RetroPI gaming controllers.
I utilized the RCA composite video on the Pi since I already had RCA only monitors in the headrests.
An external IR receiver was wired on GPIO pins using LIRC
