I have a 2020 Silverado Crew Cab that I am installing emergency lights on. I need to get a 4 awg and several 14 awg wires inside the cab from the exterior. I know there is a small grommet in the firewall that can be used, but they are not big enough for the group of wires I need to pull. What other options do I have to enter the cab? I see a silver ~3" metal plug under the rear seat on both the driver and passenger side, but they do not appear to be removable. Does anyone have any suggestions on how to get wires into the cab short of using a drill with a hole saw bit?