I'm interested in getting 12V/30A feed into the cabin of my '19 Maxima SL. I know I can get it from the battery - but routing it through the firewall seems like it would present some challenges (I have the accessory connector plug to energize relays to interrupt the 30A power when the ignition is off). I wondered if there is a 30A power source already present in the cabin to save a firewall penetration and reinventing the wheel on this.

Thanks in advance.