12v permanent plus socket

I have a rental car here, proace City, gasoline, probably 2024 or 2023. I want to convert one of the 12v sockets (in the center console or behind the right sliding door) or the usb socket at the back of the center console to continuous current. According to my previous research there could be a relay somewhere, soft can be replaced with a bridge. Only I have not been able to get out where the corresponding relay is. Can someone help me? Please no discussion about the purpose of shutting down whether this is OK with rental cars and the meaning of the whole action ?? Best regards from the South d. S.