Ignition switch needed because Raspberry Pi is a computer, and you may need to reboot it once in a while. Start button on this panel not in use, but I guess you can find use of it, like open car trunk or something.
I replaced red light on ignition board with motion sensor, so display will go off if nothing is going on.
Neodymium magnets used to secure components on the wall, so all hardware is easy accessible if something is broken or for future modifications