Gaz man

I have the alpine ex 900 head unit in my vellfire and was wondering what the sim cards for behind the screen and is it worth putting a uk sim in there

Anyone know what this button does? It lights up when i press it but doesnt seem to do much

Recently bought a vellfire and theres a few things im not sure about, theres a slot next to the drivers door for a card, google translate says etc card not connecting as it speaks to me in japanese every time i start the car, wondered what its for and is there an option for a uk card to fit in there